All the time as a child as suncream wasn't really used (by my Mum anyway) in the 70's. The beginning of summer was the worst, getting in the first burn before we started to tan, Mum had a huge tub of smelly aftersun cream and we used to pull off huge pieces of peeling skin.
As a adult I generally avoid strong sun and I don't tan so put on the sunscreen thick.
Once had very bad burns in a one off holiday to the Caribbean when I was 22 and a bit naïve about the strength of the sun (had factor 25 but out for too long in catamaran), and a couple of minor burns around shoulders/arms in Scotland when sun caught us unawares when out for the day.