Happy to jump in! Unexpected erections — we call them “spontaneous erections” are totally normal and can happen at any time in a man’s life, but are most frequent during puberty. Why do they happen? It’s mostly due to the surging hormones that occur in puberty!
By the way, just as it can be normal to get erections when you’re not aroused, it’s also normal to feel sexual desire and not have an erection! The body is a wonderful & sometimes uncooperative thing! π