Does it really matters about brains, every girl needs to know the answers,?

Okay, i love this guy and i think he likes this other l or me, and well the other l who i think he may possibly like is more brighter than me she is more intelligent without sounding big-headed i wouldn't say she is prettier than me, but i think they have more in common then we do, but he thinks i am 'fit' and have a 'good personality' and a 'nice bum'. But i am fairly ditzy but would he choose her over me? does it matter? what would you do?