I thoroughly agree with your points in the answer! However my question aims to find either some supporting/debunking citation, or a clear conclusion from experience that addresses those points in particular. — lucasgcb 1 min ago

It sounds like a classic "it's the teacher's problem - don't make it your own". If you have a hard time concentrating and you can't find a quiet place to work in then tell your teacher and solve that problem (of not having a quiet environment). — Benjamin Gruenbaum 53 secs ago

Your friend has borrowed those things which means he has to take case to give it back. If he has missed to care for that it's his fault so you should make clear to him he is in charge of doing something. If someone tells you about the party did you tell them it's your decoration and actually wasn't meant to take home? — puck 59 secs ago