Learned on their own. Uh huh. With no experience and no mentors.
Don't you know? All of the most successful people did it entirely on their own! Bill Gates was just this poor kid from the wrong side of the tracks who made it big! Elon Musk personally engineers the Space X rocket motors! Who is John Galt?
Okay, that was maybe a bit sarcastic, but yeah...everyone had a leg-up at some point. Back in the late 90s, one of the hosts of the morning show I was producing said something nice about Dick Clark in an interview with one of the trades. Not long after, we got a "thank you" note that was clearly written by the man himself. Some time later I was going through the voicemails, and a message began with "hey guys, it's Dick Clark." He was looking to do a phoner for the American Music Awards, and (after staring at the phone and replaying the voicemail a few times) we called the number...figuring it would be a flunky on the other end.
Nope. It rang twice and the voice on the other end said "Hi, it's Dick!" Later that year, we found out that he was going to be in town for an event. We did talk to one of his people, who assured us that he didn't have time to do our show. He was booked from 6am to 10pm. Then he called back himself and told us he'd make room, and showed up a little after 5am. He did have his people around, but they were unobtrusive and we got away with every silly bit or goof we could. Near the end of our time, the host asked "why are you even doing this? We're just a morning show in Phoenix, and you're Dick Clark!"
He said that when he was starting out in the business, he reached out to his idol, Steve Allen (creator of The Tonight Show). Steve didn't blow him off, but instead they struck up a correspondence where he gave Dick advice and support, and showing up to do a show with some enthusiastic kids was his way of paying it forward.