What I learned and has been the biggest lesson I've learned here in the crypto market is, never get too emotional while doing your job or business here. Getting too emotional while in the midst of the rollercoaster movement of the market cap will surely screw you and will mess up your rationality, leading you too make impulsive decisions. Since then, until now I had that lesson with me, to never let your feelings and emotions get in the way, not only in crypto space but also in every aspect of life.
That is definitely an issue many traders need to truly understand, in many other markets where the movements in the price are low controlling your emotions can be very easy since you can avoid emotions like greed and fear very easily but when this market moves 15% in a matter of hours like what it is doing now then controlling your emotions can be a real challenge and only those that have complete control over their emotions will survive.
And while many books do not dedicate a lot of time to the subject of controlling your emotions, when you trade in this market this skill is critical especially if you want to make profits in the long term.