i burn too...but then after the blisters and peeling go away i have a nice tan. i've had a few usnburns...at the beach bulding a sandcastle for 3 hours..no shirt...no sunblock...yeah...blisters on my back...ouch.
i've got a picture of one of my bad ones. i went to a big outdoor concert last september, and had my hat on the whole day (i usually wear it backwards....more comfortable for me). i guess i didn't even think about it until after...whoops

like they say, a picture says a thousand words: