This is the reason why I generally feel bad for those "two pizzas are now worth X millions" posts, as if the people who traded BTC for goods in the old days could predict the future. As such, the moment your holdings were at 10x your initial investment, very, very likely you would have sold as well, or just bought that awesome thing you could suddenly acquire with magic internet money.
That being said, do not punish yourself with the "if I had" thinking. Invest what you can and hold while you can. Taking profits is not a bad idea as well.
well, I'm sure you were having some vague ideas at the time and you weren't really aware of the value of bitcoin and how important crypto would be in the lives of humanity and civilization modern.
Because, I was in the same ambiguity as you and my pay was very high. I sold at 38k $ and I realized my guilt and foolishness. But life needs to change, so does the future. And it's best to change past mistakes.