what's the biggest mistake you made

Underneath a different post a couple of redditors were talking about their biggest screw up. Either not investing in something or getting scammed.

Since people can learn from mistakes and they're usually good for a laugh let's share them here.

I'll start (I'm cheating I have a couple): - Not selling at 69k when I had the feeling we were way over extended. Greed got the better of me. - Losing interest after the 2018 crash where I lost some money. This would've been the perfect moment to just DCA over 2 years . - I used a leverage yield farm, alpaca finance, but did it with a stable coin and an altcoin. Because of a slump in the market the leverage had me liquidated. If I used two altcoins to farm I would lose some value because of the price movement but since they would both fall I would not be liquidated. This was just me not knowing what I was doing.

So what's yours?