Anyone that has a best friend (and I'm pretty sure that covers everyone?) can remember those moments in time where you're in the car and that song comes on the radio and you both turn into giddy 13yr olds and dance from the waist up.
A few months ago, back when Moves Like Jagger just started to get overplayed, my best friend and I found ourselves pulling into the driveway. We sat there and moved like Jagger until the song was over. Then we got out of the car, went inside and resumed our sweet little married lives.
Reason #542901 to marry your best friend.