I have lost some of my coins in this trend of course. If I had x bitcoin now I have x - 1 coin. Like me there are bitcoiners who are cashing out more or less. 2017 gave us some lesson.
If you have made a decent profit on your trades, there no point in regretting that you could have gotten more, because it's impossible to make perfect trades. If you're selling at a profit, you're gaining real value and losing some imaginary value.
But is there a new lesson which is waiting for us?
Imagine someone or an institute or a group of institutions or agency who are allowed to print papers (money) as much as they can and putting all in the bitcoin market. Coins are going to their wallet until the last few left.
Private institutions like bank won't print money to bank Bitcoin, because that would be a fraud that when uncovered would put them into deep-deep trouble. Governments won't print money to buy Bitcoin, because it would just decrease the value of their fiat, that would be suicidal for them.