I read those "soloed on first flight" accounts with skepticism too, especially the ones that purported to be doing aerobatics immediately. UNTIL my brother expressed an interest.
He's been playing those very fast paced video games for years, including those online warbird Sims where you re-enact "the Battle of Britain" and the like. His first "RC" attempt was on my Real Flight Sim, and he was able to take off, land, and do aerobatics; so I said, we have to get you up on the Buddy Box.
His second attempt was on the Buddy Box with my Four Star, and he flew it easily, but didn't want to land it, and I didn't argue.
Now he had been given a Super Hots, which is an older Fun Fly type plane, and his "second" actual flight was with that plane. We couldn't Buddy Box it, so I took off and he took over. He flew it fine (and it's a fast, twitchy plane), he did rolls and loops, then flew it inverted for a couple of circuits. I thought it might be getting low on fuel and asked if he wanted to try to land it, and he did. Bounced it a little, but heck!
So while I don't always fully believe the accounts told, I certainly know they're possible.
Dennis-