I once planned to sail around the world in a smallish boat. I would stay up all hours arguing with people on the internet about whether boats I was looking at were seaworthy enough or not (spoiler - they weren't).

I was convinced that there was a formula that made music appeal to people and stayed up all hours trying to work it out on MIDI keyboards and composing software. I argued with people on the internet (I think there might be a pattern here ) about whether or not cheap keyboards and free open source software could produce music on par with high end synthesizers and professional studios.

I had another sailing episode but this time I was going to build a 14' boat and "only" go to the Bahamas from FL. Of course, late night arguments ensued...

These weren't all that recent; I seem to have reigned it in some and was mostly just an arrogant jackass the last few years. Except for a couple of times when I was convinced that I could cure any disease in my body with my mind and I could be immortal if I avoided a violent or accidental death.