I (m 24) had multiple experiences where a girl liked me ( some to the point of obsession) but as soon as I started reciprocating my interest they lost theirs. As a guy who up until 2 years ago didn’t think was worthy of being liked ( blame it on un dealt trauma) I always appreciate when someone shows interest in me but apparently I don’t know how to reciprocate. I appear pretty stoic and some girls have said that at first they thought I wasn’t interested so they kind of seem shocked when i do.