The interesting thing, though, is that for some of us who are super sensitive, there IS a big difference between the lower and higher SPFs. One time, I was out on Lake Monroe and I ran out of 70 completely. Someone finished me up with some 35, and within 20 minutes, I was burning in the spots where the 35 was, and still pasty white (with just a few sun poisoning spots) where the 70 had been.

This all just further proves my suspicions that I should just become completely nocturnal.