I beat the hills for the first time yesterday - couldn't believe it. Part was weight loss (down about 15+ lbs), part conditioning, and part learning to stroke the pedals instead of pushing too hard.
These hills are steep - gravel and nasty with big rocks in places, I am not sure I am commuting or single tracking at times.
Anyway, it was great yesterday - I ground up to the top and I wasn't even spent. This was after 2 months of slowly improving, and then all of a sudden - I was there.