For me, I really had to take time to examine what my emotions were versus core beliefs. Logically I believe that bitcoin longterm will be worth way more than it is now. I also think that the run up has been ridiculous and will eventually be corrected and I want to be ready for that.
How do I balance those? Well, I bought in low enough that I will not become unprofitable if the market corrects even 70 percent. If however the market shoots up to 30k, and I have sold even a fraction at 17, there is a chance I'll never be able to have the same amount of bitcoin. That is the regret that would be worse for me, so I avoid it.
Instead, I took a haircut- about 2 percent from all my coins and cashed it out but kept most in Gdax, so its ready to jump in again if I need it.
Also, hi! I follow you on youtube, it's great to see you on Steemit too. Thanks for all the great videos- you've been a huge part of my crypto education.