I used to be turboautistic about trains.
I travelled hundreds of kilometers to go see a particularly interesting locomotive doing its thing.
Nowadays I don't do that anymore, but I still know every single locomotive operating in Italy and I know all the combinations of lights and other railway signalling.
In the stations I used to frequent I can just look at the signals and predict fairly accurately what train will come in, how fast it'll be going and how long it'll take to get there.
Back in the day we also hung around the locomotive depot, we knew some of the guys there.
I even got to drive a couple of trains, including a really long and heavy freight train.
It was fun as fuck desu, I kinda miss it. Too bad we all moved on with our lives.