What makes you say that? Are the stories at all related (if BL1 even has a story, that is)?
I just got BL2 for Xmas. I have BL1 on PC but my PC sucks and I've only played 2 hours of it. I really don't know if playing through a 50 hour+ game is worth it just so I can "appreciate" BL2 more... unless someone can convince me otherwise.
I haven't played through all of Borderlands 2 yet, but there is little need to play the first one to enjoy the 2nd. So far, the only thing I can see useful from playing the first is a few subtle references to things like the ending from the first game. Also, appreciation of some of the world/people and how they operate may be slightly enhanced from playing the first one. Borderlands 2 is definitely fine to stand on its own.
That being said, Borderlands 1 is definitely worth anyone's time who is even remotely interested in it.