I have some serious tan lines

@walabby: Once upon a time that was the belief. Not so much anymore. Studies seem to indicate that while direct sunlight damages the skin it also has healing properties that wipe out the damage done.

@hippyjoe1955: You are partially right. Constant exposure to sunlight seems to suppress melanomas but not basil cell carcinomas or squarmi cell carcinomas. Melanomas seem to occur when a large dose of sunlight is received initially, then not much subsequent sunlight. Office workers than go to the beach occasionally seem to be most at risk. Tanning beds are very risky too, and are banned in a lot of places.
I live in Queensland, Australia, and here we have to highest number of skin cancer cases in the world.