Why do I infatuate over basically every guy who gives me more than 10 minutes of attention?

I'm a 20/F. I understand that I may have some underlying insecurities, but overall I'm a healthy person. I have a normal amount of confidence and self-esteem. However, I have about 10 "crushes" at the moment. If my friend Brent so much as compliments me after weeks of not calling me, I feel like he may just be thinking of me. If that guy I was eyeing at the supermarket were to look me over one more time, I'd spend half the night thinking about him and wondering why I didn't get his number. If a close long-distance friend tells me he misses hearing my voice, I end up with erflies and think about HIM for a day or two. All this, AND I have a frickin boyfriend whom I truly do love. What's with my obsession of men? I mean, I love them like the next woman but to this extent? Anyone have any theories and/or advice? I'm not particularly close to my father, but other important men have filled that void at some point like my grandfather, my brothers, etc. What gives?!?!