On Feb 21, 2:15*am, Jim White
I know how gliders work...magic. Is it really necessary to know how stuff
works to fly a glider? Design and build one yes, but to fly one?

Jim

Define "necessary".

If you find minimal competence acceptable, chancing that you will
never encounter a situation beyond your skill, you might get away with
an ignorance of aerodynamics.

But, if you want to achieve anything beyond that, If you want to
significantly enhance your safety, yes, it is necessary.