I doubt this statement to be true unless you're the dumbness person alive or on the forum which I can't accept that to be truth. Give yourself time and don't be in a harsh on yourself because you're better than most people here. Keeping your crypto safe depends on you being careful with your sensitive information like your seed phrase and other valuable things. To keep your crypto safe, you have to make use to hardware wallet or decentralized wallets with open source. Writing down your seed phrase and keeping it hidden away from some of the natural disasters that can happen to your home is also recommended.