I've often wondered the same thing, but have recently realized that I may have just percieved everyone else as making deeper connections with each other than they actually are. We may not feel any less "love" than they have.
I let the hottest girl I've ever seen get away too, only I've felt even worse about it as time went on. This is because I realized in hindsight that she clearly invited me to just make a move on her when we were in a study room together once, only I was too much of a blockhead to take the hint, or notice that she seemed lonely and bored on other occasions, and was therefore NOT perpetually seeing someone else, as any girl that beautiful logically should have been.
_________________
No one in the world ever gets what they want,
and that is beautiful.
Everybody dies frustrated and sad,
and that is beautiful.
-TMBG