We all made mistakes in bitcoin, either trading, investing, coding.
Other than not buying bitcoin at 0.01$ per coin when it started, what is your biggest mistake you did ?
I don't ever consider as a mistake if a person isn't able to bought bitcoins at any cheap rates it was passed since after all we didn't know what will be the price of it later. I considered that as a regret instead and to cope up with that regrets we have to act the moment we think the price is right to buy coins and "face all the possible risks" after putting money on this crypto.
Majority of bitcoin mistakes activity are those things that we already know what will be the possible output, at least, e.g investing on a ponzi or cloudmining scheme, putting money on web wallets, exchange site activities etc. Some mistakes are also human errors, like sending to a wrong wallet address, not enhancing the security of the coins, lost backup etc.