Boy” is an awesome word because it’s a word for a male that isn’t “man.” I’ve been uncomfortable with applying the word “man” to myself ever since I was 16, although that has softened in recent years, especially in compounds such as “gay man” or “femme man.” It’s so nice to have a word for male that doesn’t have those aggressive connotations (“be a man,” “a real man”) that make that word such a blunt instrument. I would say that in most contexts in which my assigned gender is relevant I use the word “boy.” I expect I’ll find one of these days that I can no longer get away with it, but who cares?