I want to introduce you to my dad.  Before I came along, he was a surfer from Newcastle.  Blonde hair, tanned skin, and a pretty good body.   Like most macho men....  he never wore sunscreen.  Back in the 1950's & 60's the ozone layer wasn't as destroyed as it is now.  And Dad would have a permanent tan... so he probably thought that was good protection.   Here's a photo of him when he was around 20 years old ⇒  
 

He got older.  The sun got more harsh.  But he was tough.  He didn't use sunscreen.

Then he noticed bumps on his head.  Spots that would change colour.  He got it checked out, and he had skin .........