There is nothing that I would love more than to be able to play the guitar as fast as I want. I see those rock star dudes and think they are so cool.  I used to think that playing fast was an impossible thing for a guy like me.  But then I started to learn my scales.  Slowly over time I learned the alternate picking technique and just started speeding it up.  Nothing crazy at first, but then more and more I sped up the metronome.  I did this until I was playing the scales as fast as my heroes.