About 45 years ago, when I was young and stupid, I was offered a trip in rather a shabby old TriPacer. The brakes (hand operated) weren't very good and the engine wasn't happy to run with the throttle closed, as I later discovered....
Having got into the left hand seat from over the back seat with the pilot in the other seat holding the brake lever with the engine at about 1200 rpm, I strapped in and was invited to taxy the thing to the end of the runway at the disused aerodrome where it had landed. Being an RAF Chipmunk student at the time, I taxyed as we'd been taught, closed the throttle and braked to a standstill planning to do some take-off checks - whereupon the engine promptly stopped.
The starter motor was somewhat intermittent and chose not to work on this occasion. Undaunted, the pilot hopped out and hailed a passing cyclist on the public road which crossed the runway. "Ever swung a prop, mate?" he asked. "No", came the predictable reply - so the pilot showed him how, got back in, yelled "OK" and the engine started first time!
By then I was beginning to realise that the pilot and his friend weren't actually that safe, so after we took off with the intention of filming the friend's house only to encounter a nasty shower, I decided enough was enough, went back and landed, then legged it and left them to it!
I Learned About Flying From That!