grass is greener

I don't understand why people are attracted to other people. Take for example my friend James. I don't understand how he can be so desperately attracted to my best friend Eleanor. She came and visited me for literally 2 days and James maybe saw her and talked to her sober for about 2 minutes. Granted, they did fall asleep together...once... and james tried a little somthin somthin with her, but I mean come on. NOTHING happened, no action. And she lives in North Carolina. And they will never see each other again. But he will not give it up. Its a little weird, but I mean it is flattering to her I guess. Especially since I tell her. Sometimes I wonder if everyone does just want what they can't have. Something to obsess over. I try to convince myself I don't. But given the situations I find myself in sometimes, (vague I know) I really do think that maybe I do only want whats not there, because when I have things they don't seem as good as I make them out to be. They let me down. Its confusing and its definitely not a good thing.
What Im saying is being content with yourself is a key to life and something everyone needs to work on. Its not just a saying you learn when your little. Its a quote to live by.