Dear Dr. Darcy:
Why is someone really interested in me when I am not feeling "it," only to lose interest once I actually AM feeling "it"? Is this person one of those velvet-rope climbers who doesn't want to be a member of a club that will have him as one?
There could be many reasons for his disinterest. Maybe he's interested in someone else, even if he's technically single. Maybe you're right - maybe he loves the chase better than the catch.
Here's a novel concept: Why don't you ask him? Getting that type of feedback can be incredibly valuable. You do it casually through email or text: "Hey John. I have a not-so-random question: I get that you're not into me. I'd just like to know - for my own growth - what changed? If it's you, that's cool, but if it's me, I'd really love to get some honest feedback."
Could be the most valuable text you ever send.
Writer's Stats: Female, Straight.