I had a few on my Trans-Am tour.
1) Riding at night off route on busy truck route, my partner wrecks in road (no helmet).. I had to pull her out of road then her bike. Very scary moment as I tried to assess the injury in the dark with trucks going and her crying! Could have been avoided, big learning situation. (wear a helmet!)
2) Greyhound "misplacing" our bikes! recovering them one day later, a good scare..
3) Police confiscating bike panniers we had hidden in a tree while off doing some hiking. We assumed them stolen!
4) Hit by car (in parking lot). Even wearing bright orange and making eye contact with driver (who was not moving) he slammed the accelerator (accidentally I hope) as I passed his vehicle, crushing the front end of my bike, though I escaped unharmed.
5) Swimming in Johnson's Shut In SP in Missouri (highly recommended stop on Trans-Am).. heavy clouds rolled in, locals advised us we could continue swimming. Moments later were all received a heavy jolt as a lightening bolt touched the water! Very scary.
Every single one of these could have been avoided, but hey, life is for living and learning right?