If we are considering bitcoin to be in the mix of investments, it seems to me that framing our dilemma in terms of pulling out and getting back in does not seem to be a good idea.
One of the first things to consider is to figure out how much you need, and then continue to build towards getting how much you need and perhaps more than you need, and then once you have reached what you need or more than you need, then you will have more flexibility in terms of figuring out how much you might pull out in order to offset large price swings, and hopefully once you figure out how much you need, you will be careful in regards to going back below how much you need in the event that you are even willing to take those kinds of gambles at all.
There are likely some other kinds of investments that you are mostly just building (just like in bitcoin) and mostly not selling, even if you might shave some off from time to time, whether referring to properties, equities, commodities, or cash equivalents (like bonds).
You are correct on that, as one of the best ways for an investor to succeed is to take their minds off selling at every given time and instead focus on how much could be accumulated and how to reach those targets. This is exactly where my explanation comes in. I do believe the time spent figuring out how to accumulate more should be accumulated and when to pull out some in order to offset large price swings is never considered a boring moment, as one needs to be busy calculating and also putting their decision into practice.
Everyone is right on there own thoughts, as an investor who puts his/her money on an investment, your mind must be on that investment or the capital it self not the profits, hope you get my point? The capital because is the hard earned money the investor used to invest, not the profits because the investor is not well assured of it, but keeping your mind away from selling your coins is very very important thing to partake, holding your coins makes the profits more bigger for a proper time to sell, it might be tempting to sell your coins if that's the fist time for the investor to join the crypto world.