I began flying with standard private pilot training for the time, on flapless Aeronca fabric wing birds and such, later transitioning to all-metal Cessna 150s.
But, one of the members of my club reported how he had been flying 'over the top', as is permitted in the USA without an instrument rating. He was getting dangerously low on fuel, with solid clouds under him as far as he could see. He had to be rescued by a Hercules, who led him down through the clouds to safety. On the principle of learning one more thing than you think you will ever need, I got a night rating, which covers keeping control of your bird on instruments in the air, including in clouds.
Then, flying a shared Cessna, I experienced a total Nav/Com/ADF failure. I was VFR so was in no difficulty, landed at a NORDO strip and got the offending power supply fixed. But I asked myself, what if I were in the clag when that happened? A session with my instrument instructor followed, learning how to use the compass at the top of the windshield for stability in direction (step on the wire), keeping airspeed (indicator powered by a pitot tube) in the middle of maneuvering range with elevator, and keeping the aircraft level by 'seat of the pants': no sliding side to side.
Finally, a fellow flyer had a large bug hit his pitot tube which blocked it, disabling his airspeed indicator. How to control airspeed in the safe region without an indicator?
I was flying U206 cargo birds to the Moose River Mosoni at the time, and remembered a Cree boatman who took me out into solid mist on James Bay, turned the motor off, and waited until my listening turned into feeling the land hidden in the mist as he did.
With a fellow pilot in the right seat of a 172, I practiced feeling the air the same way, with eyes shut to concentrate. When the airspeed got too high the sound in the cockpit took on a sharper edge, when too slow it sounded dull. When the bird started to bank, tilting my head to one side then the other revealed that it sounded higher on one side than the other; tilting the ailerons to the low side levelled the plane. After enough practice, I could fly with eyes shut for as long as I wanted and maintain stable control.
Pilots in my circle had the saying, "The best pilots never have to show it." I never needed this skill for real, but I was never on my last out either, no one ever needed so much as a band-aid as a result of my flying, you never heard of me as a pilot, and that's exactly what we all wanted.
And, I've never forgotten sitting in the near-silent mist of James Bay, learning that our mind can transform hearing into feeling.
Addendum:
On 23 July 1983, one Capt.Pearson was notified in Montreal by the prior PIC that the fuel quantity indication sensors on the 767 he was taking over had not been repaired, so the fuel had to be dip-sticked prior to takeoff. Pearson didn't do it, so an error by ground crew in loading fuel by pounds instead of kilograms wasn't caught and the aircraft ran out of fuel mid-flight.
Pearson then called on his exceptional skills, not just as an ATR but also as an experienced glider pilot, to land the plane safely.
But, he failed our test: he had to show it.