I have always found that a very logical argument for selling. For example my mom had a health scare back in 2018, she was scared to have a heart condition, thankfully nothing came out of it but I had to cash out almost 50% of all my bitcoins during that time, paid all the hospital bills and if I kept that now it would have been about 50k dollars, but at the time it was like 8k or so, I have missed out on 42k profit because of it. However do I feel regret? I certainly do not, because I needed to do that, and knowing that my mom is healthy and doing fine right now (except for a minor hernia which is really nothing compared to heart condition) that is worth more to me than any amount of money.
If you "need" to sell because of a reason, that is fine, and that is what I do, I buy because I think it will go up, and I will only sell if I need the money and not because I believe it would go down.
Yup! I mean, I love "being in Bitcoin", earning it, using it, whatever, it rocks my boat. But I still try to remember it's still experimental. Looks really successful so far, and long may that continue to be, but at least if it ever goes to zero, spectacular crash, whatever, I'll at least want to look back and say the experiment did me some good. Paid for bills. Holidays. Made me look cool, whatever.
So maybe we've got to end up spending 50% of our stashes. Maybe when Bitcoin goes to $1 million, we miss out on the big pay day but it's all that using and spending and selling that helped get us there, right?