I've witnessed ball lightning twice in my life. None of the crazy UFO style stuff, both cases the lightning was arching between clouds and just sort of balled up and hovered there for a few seconds before fizzling out.

A little more repeatable, I once stopped in the middle of nowhere in west Oregon at 2am. We pulled over on some rural road, turned off all the lights and just looked at the sky. It was the first time I'd ever been somewhere I couldn't at least see light pollution on the horizon. I grew up in a rural area, I'd always shown off the stars you could see out there, but the awe I felt in that perfect darkness seeing more stars than I'd ever managed before has actually soured my love of the sky. The sky at home looked so dull after that. I live in the city now and rarely see any stars, somehow I don't mind.