Yeah, it's crazy, and mostly a marketing ploy to get us to spend more money on sunscreen. The sun damage we get walking to our cars is minimal.
I buy one bottle of sunscreen a year...for a family of 6...and we never use it up. I replace it each summer because I figure it's expired. We mostly just use common sense, seek shade, wear hats and other protective clothing...and stay the hell out of the sun at high noon. None of us ever lay out to bake on purpose. That just seems stupid.