Sounds like Senku had a lot riding on him back home. Sitting still probably felt like he wasn't doing enough to help. Or he'd always been a busy mind.

"Chores ain't bad. So uh people just put in for what they wanna do or are we expected to do certain things?" Pitching in for chores was fine as far as he was concerned. He was used to that sorta thing anyway. At the fire station everyone had to do their part to keep it clean and put together, they all worked and lived there after all.

Same idea for the train.