This happens to me a lot. Not even just high school, even college and work. Which absolutely blows my mind everytime its brought to my attention cause I never thought of myself as desirable. Largely cause I'm an opinionated anti-social misanthrope :penciltrick:
I tend to tell my crushes if I like them but its rare for anyone to catch my attention so luckily I don't have to bother with this issue too often.