Grew up in Australia, at a time when people hadn't yet realised about the dangers of excessive sun, and have hundreds. I can't imagine having none. Every time I look, a few more seem to have appeared.
I go once a year to a dermatologist and have them looked at. Have had three removed so far. One was cancerous, but not melanoma.
One of my brothers had a melanoma removed from his leg. When the doctor saw it, he booked the hospital appointment for the very same day. That brother is pretty paranoid about avoiding sun exposure now!
One of that same brother's classmates died from skin cancer when he was only in his earlier 20s.
My father has been having skin cancers removed from his face on a pretty much ongoing basis for about the last seven years. And he hasn't exposed himself unprotected to sunlight for decades now. So the damage from decades earlier is still affecting him now.
Bottom line: if you have lots or are at risk, get them checked out once a year or once every two years by someone who knows what they are doing, even if the doctor has a bad attitude or makes you feel bad. Being subjected to a bit of attitude is better that dying. And do it even if you haven't been in the sun lately.