Tinkering with things is a fantastic way to learn. And a desire to tinker for the sake of understanding is a really good tell for a smart problem solver.
Every job I've had has been because I played around with some technology for fun, and then ran into people who had a need for it.
Playing with code can also be relaxing. In my normal work, the code that I write needs to be reliable, maintainable, and performant. Buy playing stockfighter is a way to have fun without the burden of any that. I can do really stupid stuff, just for the joy of it. Heck, I hooked up a spam filter to one of the levels and won. Or built a minecraft stockfighter hologram visualizer.