When I was a kid, adults (even very successful ones) went out of their way to tell me how difficult and terrible and arduous being an adult was. And perhaps it was, for them.
But my childhood was pretty terrible itself, and nothing I’d ever want to return to.
By comparison, while not always a cakewalk, being an adult has been a pleasant, fairly easy, sometimes boring but mostly great experience. I’ve seen amazing things and done many things people assured me I could and would never do. None of the horrors that other adults assured me awaited ever occurred, nor are likely to.
The adults as usual were wrong — my youth while not wholly unbearable was pretty unpleasant, while being an adult has been mostly great.