Am i missing something?

People on facebook are moaning about being sunburned. Sunburned, sunburnt? Anyway, i dunno, i just don't get it. I mean, you have to be out in the sun a fairly long time before it starts to turn you red right? Surely people who get sunburnt/ed, have been sunburnt/ed before? I think?
I was at a car boot sale on Saturday (more on that laterr) and i seen the reddest arms I've ever seen before, on this woman, it looked really fucking bad. And i seen a woman outside a pub today who was also red as fuck. But how hard is it to work out that hot sun = roasted flesh? All you have to do is just slather on a bit of suncream.
Personally, in my 22 years on this planet, I've managed to notice/figure out/realise, that with my heritage, I'm a bit of a lucky bastard in that i just don't burn in the sun. I know last year on one of the few days it was sunny, i came home and when i looked in the mirror that night, noticed that my cheeks were a bit red. It was pretty funny, and i was surprised cause it'd never happened before, but it didn't hurt, i didn't even notice it had happened till i looked. Subsequently, i was aware that maybe i should be careful about my face in regards the sun right. And I've been alright ever since, i know if its a bit hot now, simply keep my face shaded. Simples, as that Russian meerkat would say.
So, i mean, is it really that hard to comprehend? Why the big deal, i don't understand how so many people end up sunburned each year, and then we're all lumbered with listening to them complain about it like fucking idiots.
Maybe its cause the ozone layer is getting thinner every year, thus every year the sun gets hotter, thus people who have never been burned before, are getting burned. I'm open to that, but i dunnoo, ack. Just, surely all these sunburned people I'm seeing, surely this can't be the first time they've ever been affected? People must know their skin type, know this might happen to them?
Maybe I'm over-estimating people. Maybe people are fucking idiots.