Yeah, its just possible. Anything is possible.
After 50 (!! )years of playing gigs and never having worked an engagement that required or benefited by a Contract, I can only imagine the HEIGHTS of your esteemed career, and the MAGNITUDE of the venues you have worked at!
C'mon buddy, I'm certainly no major rawk star, but working in ANY professional capacity in a professional environment generally does require a Contractual Agreement between the Venue and the Entertainer(s).
"Having fun" with your "thousands of gigs" of "actual experience" only means that those actual experiences are probably quite local, low-profile, and mostly amateur in nature.
Nothing wrong with that. Most Musicians are non-full time amateurs.
At a certain level of Professionalism in Bookings, a CONTRACT is REQUIRED, even if you yourself are good with a handshake. It doesn't work that way once you step outside the "Joe's Bar" gig world. Really. It doesn't.
Take
that to the Bank, "Mr. 50 Years"
Or don't!