Jack Ma advises to learn from others' mistakes rather than their success stories.

So i kindly ask you, guys, to share your biggest mistakes (or mistakes that you think the others can avoid) in trading, securing your coins and etc. in this thread. I hope "new comers" will be able to learn a lot from this thread 


Let's begin with me: Mine is almost a cliché but still there are a lot of people who do this mistake - I blindly followed some traders on twitter which cost me 30-40% of my funds