If I was interested in you, you would definitely know it. If you didn't reciprocate? oh you ain't feeling me? fine, it costs you nothing, pay me no mind. Which RARELY happened.
Everyone isn't for everybody to begin with I just accepted very early that other people had the right to reject me like I had the right to reject people for I didn't feel any attraction.
I actually expressed my interest in someone a while ago and got turned down. Did it hurt? YES I really did want to get to know them better but I live by the saying "you only get one good time to reject me". Now I'm grateful they did that because I'm now interested in someone else and that possibility looks like a much better fit for me.