I've been hit and not really hurt, too much. By "not hurt" I mean I didn't go to the ER, no stitches or broken bones. I had a HUGE bruise above my knee, bruised back and shoulders, road rash, and whiplash like crazy. I missed a few days of work and I didn't ride my bike for a good 2 weeks afterward. The leg bruise hurt for at least a month. The swelling lasted for days, and after that it was a nasty hard purplish-brownish-black spot. It was about the size of an orange.
My bike, however, was completely mangled.