That's a core question, right?
You feel attracted to a guy and he rejects you.
You rationally know it's pointless to pursue him but part of you obsesses about him.
Here are some possible reasons:
Imagine your life 400'000 years ago.
You are in a tribe.
Most men are taken.
There is one left.
10 women pursuing him.
Now, in those days being without a man is being in danger.
You might be attacked by wild animals or rival tribes.
Without the protection of a man, your survival is threatened.
In fact this man you are pursuing could be your only hope to survive the winter as he will hunt and bring back food.
You see the dilemma in those days.
Being with that specific man might have been your ONLY chance of survival in many situations.
Now, back to today!
When you are really fixated on one specific guy, maybe it is the result of these old patterns.
A lot of your emotional reactions in your love life could be tracked back to this type of cave behaviors.
It know, it takes away a bit the romantic and passionate dimension of what you feel, right?
Well, not totally.
This original instinct is a primal impulsion.
Around that, romance and passion build up.
These are real of course.
It's like with sex.
The primal sexual instinct is simply a need to procreate.
It's an animal instinct embedded in us.
But of course, there is way more to sex than just an animal instinct!
You have all the beauty, refinement, aspirations that developed around this original instinct.
When you obsess with a man, the romantic beauty that you experience is real of course!
Tracking back these obsessive feelings to the place where they originated might give you a fresh understanding over where these emotions come from.
... And especially why they seem so intense!