Things like fans just irritate me, I guess I'm either not used to hearing them or they're just an intrinsically annoying sound. Like now I can hear a little fan whirring away in my iMac and it's like a constant buzz. I just want to turn the thing off to stop it.
My bedtime routine is basically put phone on charge, turn off lights, put on earphones and stick a podcast on until I'm about to sleep. If I don't do that my mind will race as thoughts kinda all come together if it's not occupied. :p