1 - Lesson one: Do not buy a coin from the highest point of that candlestick
Then I thougt It was an oppurtunity for me to buy more coins from that burning one! The coin of the future! All-in to the same coin second day! The next day another %50 fall!
This isn't necessarily bad, it completely depends on the situation.
e.g. It's mid December, and you bought BTC at somewhere near it's peak (16k-19k); it's fine in my opinion if you're just planning on holding on to it for decades and if you think bitcoin will rise above it in the future anyway.
Still a great tip though, but geared towards more of short-mid term investors.
Isn't it better if you bought some BTC on 8k ? So I'll stick to my learned lessons, I may buy BTC anytime, but never on the highest point! Never buy with full of my usd savings, need to save some to buy later on. I buy gradually, I sell gradually.