If you think you've made a crazy mistake before, then you haven't seen this.
In November 2017, a developer accidentally destroyed a piece of code that 587 Ethereum wallets depended on.
One mistake froze 513,774 $ETH worth over $150 MILLION at the time.
Among the victims were the funds raised in Polkadot's ICO. Its wallet held 306,276 $ETH, now worth $717.92 MILLION.
The $ETH is still sitting in the wallet, visible to everyone, but the funds remain inaccessible.
And the developer's explanation on GitHub was "I accidentally killed it."
Could you live with making a mistake that expensive?