This ones:

Allowing someone to manage your investment

Lost keys due to HD failure or Theft

I have an old Samsung S3 Mini with 5 bitcoins.... I forgot about them and one day they became 100k USD. The wallet was Blockchain.info and I didn't do the thing right when I created the wallet.

And the other time I lost crypto was because I tristes a third party to take care of the prívate keys.

Lesson learned in the hard way. Never again, take care of your cryptos!