Riding a bicycle on the streets of Chicago is an adventure. It’s a lot like playing a video game, except that you might actually die.

About once a month I almost crash because somebody in a parked car opens his* driver’s-side door into the bike-lane. (*The English language has now existed and developed and changed over the course of several centuries. Can we finally just invent and agree on a gender-neutral third-person singular pronoun that actually indicates a person?)

The fact that people carelessly open their driver’s-side doors into the bike lane is, of course, annoying. But even more annoying is some people’s behavior after this happens.

In about 75 percent of these situations, the person is really nice and apologetic about it. As soon as she sees me approaching on my bicycle, she’ll close her car door and say some sort of apology. And I make it a point to be polite in kind. In fact I’ll usually say, “That’s okay,” not in the sense that it really was okay, but in the sense that the person has acknowledged the error and is holding herself accountable. Presumably this person now gets it and will be more careful in the future.

But the other 25 percent of the time, the person will see me approaching on my bike, and he’ll just leave the car door open, and maybe even come out of the car. Basically he’s pretending I don’t exist—as I’m clearly hurtling straight toward his open car door. And I’ve experienced enough of these incidents now that I think I know what’s going on: the offender simply doesn’t want to admit that he was wrong.

I think that the logic is as follows: I see you, bicyclist, but I’m going to pretend you don’t exist. I’m going to leave my car door open, even though it’s blocking your way. And you will have to either stop in the bike-lane, or swerve around me and into automobile traffic. You may get hit by a car. But it’ll all be worth it, because I won’t have to admit that I should have looked before opening my car door into the bike-lane.

Chicago has an excellent, 15-mile path along the shores of Lake Michigan. I will call it a bike-path, though it is designed not only for bikes but also for joggers, roller-bladers, walkers, etc. Riding the lakeshore bike-path is an entirely different kind of adventure.

Though it too is like playing a video game except that you might actually die.

When the bike-path is crowded, it’s an uninterrupted river (not a sea, because it’s narrow and long) of bicyclists, walkers, joggers, runners, stroller-pushers, cooler-draggers, PDA walkers, perpendicular-gazers, Segway tourists, pterodactyls, and electron-cloud families.

Now I will define some of the terms from the above list:

The PDA walkers (PDA here stands for Public Displays of Affection) are usually a young couple. Their world is all magic and spring and passion. In fact, there is so much magic and spring and passion, that there’s no room for acknowledgement of non-lovely things such as other pedestrians or bicyclists or—heck—any people at all who are not members of the PDA walkers’ exclusive two-person club.

The perpendicular-gazer is the person (usually a pedestrian—sometimes, even more distressingly, a bicyclist) who is moving in one direction, but looking in a direction perpendicular to the direction of movement. This person is moving either northward or southward, and is looking either eastward (at the Lake) or westward (at the skyline). I agree that the Lake and skyline are beautiful. But it turns out that both are just as beautiful from a few feet off the bike-path as they are from on it.

The Segway tourists are a group of 10 to 12 people, all on Segways. The Segway tourists actually tend to be very respectful of the space—they usually go single or double-file. But there are still two annoying things about the Segway tourists. The first one is simply the fact that they’re a bunch of people on Segways. The second is that you see them ahead of you, and you catch up to them, but then once you catch up to them you find that even though their speed has remained constant, somehow they’re now going exactly the same speed as you. This violates the laws of physics, but it’s true. I’ve seen it.

Some roller-bladers feel that they must take up the maximum space in the left and right directions. The right leg shoots out to the right as far as possible, then the left goes left as far as possible, and so on. As an homage to the wingspan, I call these people pterodactyls.

The electron-cloud family is an extended family of seven or more people, all walking erratically so that as a group they take up the entire width of the bike-path. Picture seven or more people, from three or four generations, all walking on a bike-path as if they’re drunk toddlers, and you’ll have the right idea. Normally when you (as a bicyclist) pass somebody, you pass on the left, and just before you pass, you call out, “On your left.” But with the electron-cloud family, “to the electron-cloud’s left” is equal to either “Lake Michigan” or “Lakeshore Drive.” So you simply call out, “Coming through, please,” and weave your way through the electron-cloud. And hopefully you don’t strike any drunk toddlers.

And here are a few contingents that I’ve only witnessed once each. So I think it would be disingenuous to imply that they are legitimate categories, but I will still name them.

The helmet-holder: I once saw a woman riding her bicycle and holding her bike-helmet in one hand. Now, here’s the deal: even for a safety freak like me, laziness sometimes trumps safety. For example, I once was leaving my apartment to go on a bike-ride, and on my way down the steps I realized I’d forgotten my helmet. I simply kept going. Apparently I’d rather sustain massive head injuries in a bicycle crash than walk back up three steps to get my helmet. However, this woman was actually creating extra work for herself in order to be unsafe. This made no sense to me.

The tree-grove: This is similar to the electron-cloud family, except that there is no locomotion of the group OR of the individuals. The people are all just standing there, taking up the whole bike-path. The one time I saw this, there was, admittedly, a sense of temporariness about the situation. It appeared that the group was actually in process of crossing the bike-path, to get from the beach to Lakeshore Drive, but in the middle of this process something had happened that made the people pause. The people who were further toward Lakeshore Drive were looking back at those were still on the bike-path.

The human chain: Once there were four females (two women and two girls) standing side by side and holding hands, walking toward me as I biked toward them. They were four-wide across the entire bicycle path. They were an impenetrable human shield. A four-by-one matrix of humanity. And I thought, what is this, a game of Red Rover? “Red Rover, Red Rover, send that guy on a bike right over.”

On my bicycle I’ve witnessed a lot of road-rage—involving cars, pedestrians, and bicyclists, in all combinations—including the homogeneous combinations such as bike-on-bike.

And I’ve learned a strategy that has proven effective in diffusing road-rage: Whenever I am involved in an incident that could result in road-rage, I always immediately apologize, sometimes with humor, even if the incident was 100 percent the other person’s fault. The reaction from the other person is almost always positive—even if the incident was mostly my fault—and I am convinced that on several occasions this strategy has dramatically reduced the probability of a road-rage type outcome. And this benefit comes at little or no cost to me.

I’ve noticed a phenomenon I will call the Bicyclist’s Law of Conservation of Momentum. The basic idea is that many of a bicyclist’s actions can be explained by an instinctive desire to conserve momentum—that is, to avoid letting momentum dissipate.

On a particular bike-ride on the lakefront, I was exceptionally thirsty, and craving my next drink of water. And then I saw a water-fountain. But it was right at the bottom of a hill. So I rode right by it. I chose remaining exceptionally thirsty over giving up my downhill momentum. This moment was when I first thought of the idea of the Bicyclist’s Law of Conservation of Momentum. And then I started to understand that the Law explains other common behaviors of bicyclists.

One of the worst habits of bicyclists is the habit of riding right through stop signs and red lights. Much of motorists’ annoyance with bicyclists can be traced to this behavior, and on this issue I side with the motorists. And of course, this behavior can be fully explained by the Bicyclist’s Law of Conservation of Momentum.

Another annoying habit of bicyclists is something I call the Chameleon Complex. This condition manifests itself in bicyclists switching, on the fly, between “vehicle” and “pedestrian” status, also in servitude to the Bicyclist’s Law of Conservation of Momentum. The most typical scenario is that a bicyclist is riding along happily, on the street, enjoying “vehicle” status. But then when the bicyclist encounters a red light, he slips to the right a few feet and seamlessly switches his status to “pedestrian” and bikes through the intersection, and then on the other side slips back to the left and reclaims his “vehicle” status. This behavior is another one about which motorists are justified in being angry.

Once you get used to using a bike as your primary mode of transportation, on those rare occasions when you have to walk somewhere, the walking seems unbelievably slow. When I have to walk somewhere, as I’m going, I’ll look down at my feet and think, seriously? If I were on my bike, I’d be a mile up the street by now. This is going to take three years.

Sometimes when you’re biking on the streets in an area you don’t know, you’ll suddenly find yourself on a street that’s almost a highway. There’s no bike lane and the automobile traffic is moving at around 40 mph. And the cars are whizzing by you, within inches of you. You’re stuck riding in that 12-inch-wide strip of concrete between the road and the curb. I call that the broken glass lane. Because somehow, all of the broken glass in the world is in that lane.

I bought my bicycle earlier this summer at a used bike store for $100, after not having ridden a bike for two decades. My first ride on my new-to-me bike was a mile long, and I was physically spent at the end of it. Since then I’ve logged hundreds of miles, and I now regularly ride 20+ miles at a time. I’m saving money on bus and train fares, I know the city better, and I’ve lost 10 pounds.

That $100 is one of the best investments I’ve ever made.

And while there are lots of negatives when it comes to riding one’s bike in the city, I have learned to accept them and work around them, and sometimes find humor in them.

They are all part of the adventure.