Gliders, especially slopers will teach everything anyone could need to know about airplanes.
The experience of almost limitless flying time.. not dependent on the fuel supply, just Ma Nature's wind lets flight past hours happen. One takeoff, one landing, hours in between.
You really get to feel the airplane, and learn how to fly it in all orientations.
And you get to re-experience the innards... fly, repair, fly, repair.....
Adjustments are easily done. Toss, evaluate, land, change, toss, evaluate, land... and repair...
If it can't fly on the slope, it can't fly!