Last summer I spent more time outside than any summer since childhood. I wore a floppy hat and a T-shirt, but no sunscreen. I never burned once. I attribute some of my success to avoiding vegetable oils and taking Vitamin D supplements in winter.
This year I got cocky, and went to the water park with no sunscreen or cover. Every place normally exposed by a T-shirt was just fine. I don't think of myself as tan, but I had just enough of a hint of color that my skin had natural defenses against the sun. However, my pasty white shoulders got a pretty bad burn in 2 hours of exposure. So I renewed my research a bit. My burn may increase my chances of getting melanoma, but overall it may not be a total loss. Regular moderate sun exposure (such as working outdoors) actually prevents internal cancer, and general overall health.
My new plan is to try to spend at least a few minutes outside each day in either my swimsuit top or my sun dress. I don't really find sunbathing pleasurable, and I don't want a deep tan, but I need to get my pasty white shoulders a little bit of defense against longer special occasion sun exposures.