Why can't all 4 of these be right? "A little too insane" defines every bubble in hindsight.
Point to a bubble w/ a collapse and I'll give you a set of statements that are "a little too insane" such that fundamentals don't hold up.
My guess is you're gobsmacked by the idea that the fundamentals don't hold up and are saying "how can anyone be that stupid?". They didn't in 99, nor 08, nor Gamestop, nor now.
Everything can be wrapped under Greed.
[Edit] Full disclosure, I'm no better - I've lost money chasing greed.