How did we get here?

Tonight I'm at church at a coffee house with lots of music and photos and paintings... I mean it was really awesome but while I was there I ran into someone who will remain nameless who now has a girlfriend who will also remain nameless and I just don't get it. How do people end up together? I know people say, "Oh, opposites attract." Really? If I'm being realistic, I want someone who complements me, not someone the complete opposite of me... what if I like boxing and he only likes football? What if I hate (strongly hate) Panera and that's his favorite resturant? I mean I realize that relationships is give and take but I don't think that meant, "Completely give up who you are and become someone else in order to please another person." I mean that nameless boy is not doing this (To be honest, I just had to correct myself because I just put that he is doing this so maybe I'm subconsciously think he is?) but I do think he has partly become someone else in order to be with her. This nameless boy is quite the musician and he enjoys that in the other person as well, which she does but tonight as he was singing, she left the room? I mean what? Supportive? Caring? Listening? Not to say that she's not those things because she does seem like a nice, passionate, pretty, got it together girl... but how did they get here? How do we end up with the people we end up with? Will I end up the same way? Will I be with a guy who just doesn't make sense for me? Will people look at us and say, "They're cute and sweet, but they just don't make sense."? It would be like Jake marrying Vienna instead of Tenley, it just shouldn't happen.... and now that I'm finished with that, I think I'll go cry and scream saying, "Maybe this is why I'm still single!"
With as much sincerity as I can round up at the moment, Melis