Earn crypto, don't buy it!
The number one lesson I have learned is that it is better to earn crypto than to buy it. Buying crypto is the least sustainable and most stressful way to hold it. Prior to Steemit, it was much much harder to earn crypto than it is today. Today anyone who really focuses on earning crypto can figure out ways of earning it. So from this lesson I suggest to anyone to focus on earning rather than buying crypto.
You are almost guaranteed to lose a private key, prepare yourself!
The number two lesson I learned is there will be losses. Even if you trade perfectly and invest in all the right coins you will eventually make a mistake. Either you will get hacked, or you will lose a private key which later on turns out to have been worth hundreds of thousands of dollars if not millions. This is not avoidable and it happens to most people in crypto. One of my first experiences in crypto was getting scammed, and losing around $500 trying to buy Bitcoin. I lucked out and got my money back somehow by complaining to a middle man in the chain but I did not get my coins.
Have patience, time is on your side if you got in early
The final lesson is patience. People who do not have patience will not do well. It takes time for your favorite tokens to go up or become truly useful. It can take a few years before it is really developed. On the topic of losses, I lost access to a private key just recently worth over $1000 due to unknown unexplainable technical error. The difference is now that I earn crypto pretty much 24/7, I know eventually I can get it back over time.