I love reading while I'm on a noisy train. I have difficulty understanding speech if it's noisy and/or several people talk at the same time so other passengers talking to each other or on their phone don't bother me most of the time. But I can clearly see that I'm loosing focus if the train stops for more than a minute or two. I then start hearing people's conversations like they just started talking at the same moment or, if there's nobody else or everyone is totally quiet, my own thoughts and immediately loose focus.

Oh, an yes - I was diagnosed with ADHD like 15 years ago while in early twenties