I'm riding up and down hills 80% of my commute - they're modest but frustratingly long. Still, it's only 2 or 3 miles and a couple hundred feet total.

Worst hill I ever had to tackle was coming up Main Street and Triangle Street on the east side of Amherst, MA, from East Village to UMass. It seemed like a minor mountain when I first started riding that route. Funny to remember that these days.