>> you need other types of unrelated input for your brain to make a different type of association Or maybe it's even simpler: conscious mind stuck on hard pro

>> you need other types of unrelated input for your brain to make a different type of association Or maybe it's even simpler: conscious mind stuck on hard problem starts to work as broken record - you are repeating the same thoughts, reconsidering the same wrong solutions all over again. Focusing on something unrelated frees your uncounciousness to try something else.