Steve Foley writes:

I have flown many different aircraft, and have never had to ask someone how
to trim the plane.

Nothing obliged me to ask. I could have simply used trial and error.

If you don't have to ask someone how to trim a real plane, then it follows
that no training is required to do so, in which case a pilot has no advantage
over a non-pilot when it comes to trim, since everyone does it instinctively,
without having to ask anyone anything.