Traffic Lights for Imaginary People

For as long as I can remember, I’ve held imaginary conversations in my head. Occasionally it’s imaginary arguments — which I always win — although I’ve moved away from those. Now, any time I’m alone, I explain things.

Yesterday I went for a walk. Along the way, I spent about 20 minutes explaining traffic lights to nobody in particular. Another 40-minute chunk was dedicated to explaining recursive sequences.

I have no idea if this normal. Imaginary arguments? Definitely. People joke about that pretty often. But explaining things? I honestly don’t know.

I’m quite confident that this practice is the #1 way I learn things. I’ve certainly heard people say that teaching is the best way to learn, but I’m going to make the case that you don’t even have to teach real people. Simply explaining something to an imaginary audience lays clear all of the gaps in your knowledge and helps to fill that knowledge in.

In particular, my explanations are usually about how to invent something from scratch. What problem are we trying to solve? Why are other, more obvious solutions ineffective? That sort of thing. Here’s an extremely condensed version of the conversation I had about traffic lights:

If you’re inventing a system of roads that allows people with cars to get places, intersections are pretty crucial. Building bridges at every road crossing is expensive, so you’ll need a way to ensure that people don’t crash.

The obvious solution is a simple convention: Everyone stops at every intersection and they all take turns. That’s a stop sign. This is awesome if you don’t have very many cars. But when traffic becomes heavy, cars start to back up.

How do you speed up intersections? Taking turns is the big time sink, so you want to batch people together. 10 people in one direction, then 10 people in the other. That sort of thing.

The trick is figuring out how to coordinate the people. There is no longer a simple rule for when to go and when to stop, and that’s a problem. Some sort of central coordination is required, and the traffic light is a great solution. Each individual still follows a simple set of rules: If it’s red, stop; if it’s green, go. But now they’re coordinated!

This is great until someone needs to turn. (And the explanation continues. Right turns. Left turns. (Why are they different!?) You get the gist.)

Keep in mind that the actual conversation was way less polished than this. I’ve edited it down to preserve your sanity. It took you 2 minutes to read it but it took me 20 minutes to explain it. That’s a 90% fluff factor.

I would like to recommend this approach to everyone. If you can pull it off, it’s an excellent way to learn things. (In particular, it’s a great way to truly grasp the things you thought you already knew.) However, I’m not entirely sure how this will sit with other people. I find these conversations inherently fascinating, but if you don’t feel the same then the approach might not be for you. Interest is impossible to fake. Fortunately, most things are far more interesting than they first appear. Just try explaining anything to the invisible people in your mind and see for yourself.