You have no idea how happy i am to see this thread. This is actually one of the main forms my obsessiveness takes, and i spent hours yesterday trying (and failing) to write a reply about it for another thread. I'm glad I'm not the only one who has experienced this, though mine is a bit different in that...
1-it happens with people i haven't met (celebrities, etc), as well as people i have, and
2-it is definitely romantic.
It also occurs exclusively towards guys, even though i'm bisexual. The fact I'm male myself might have something to do with that.
Basically i come across a guy I'm attracted to or who's nice to me, and i develop something half way between a crush and idolization for him.
I start to think about him everyday, to talk about him all the time, to long for his approval and fear his disapproval. If it's a celebrity, I'll also collect pictures/DVD's etc, quote lines from his movies randomly, and so on.
I've always been embarrassed about it because i thought i should've outgrown this kind of behaviour by now. In what was a personal low point in my life, last year someone called me 'too intense' and even 'predatory' because of it. It bothered me for weeks that people thought of me that way, and I felt like a silly, immature creep. I'd never hurt anyone, i just tend to either bottle my feelings up or express them without any kind of awareness. I also guess I want affection and reassurance from the people i'm fixating on.
In my last job there was a guy i felt this way about. The minute i saw him i could tell he was going to be trouble
We talked a little, and he seemed nice, and made me laugh. We only worked like 3 shifts together, but it drove my stress levels up so high that when i left, while i was sad i wasn't going to see him again, i felt a strange sense of relief. I'd no longer have to feel insanely anxious or self conscious around him, or handle the competing feelings i had, both craving for his attention and being terrified that he'd reject me.
Most people would've just asked him out, but I couldn't do that. When someone told me i should 'just ask him out, you never know', i felt like they were telling me i should "just" wrestle a tiger because, hey, I might win. 6 months later, i now find myself wishing i had, but knowing if i could, the only anxiety would come back.
As you can imagine, it makes both friendships and romantic relationships difficult, since i either struggle to approach someone i want to date, or wind up developing crushes on people who are nice to me, making the friendship awkward until they push me away.