In fact, you could sell all or almost all your coins, but only to buy back later, during the bear market. So far, Bitcoin cycles have been quite predictable, so it shouldn't be too complicated to choose the right timing for this. If it's so easy, why not everybody is doing this? The biggest issue is that most people who wanted to sell have sold already, or bought back much less than they converted to fiat and so they don't have coins to earn enough to become filthy rich.
Indeed, some people have their own take profit targets, as well as their own financial management. In this case, financial management is very necessary. There are several patterns for long term holders when facing the next bullish era.
Some of them are those who only take part of their profits, so they can use the other part for longer term investments. And use the other part to take profits, which can then be used to ash out certain needs and also some for buybacks.
The next is a condition where someone sells all their Bitcoin assets during the bullish era and then divides a certain percentage to cash out for certain needs and certain plans. And the other part is used to buy Bitcoin again during the bearish period.
In this case, because I only have a few Bitcoins, I will choose the second method. Or even sometimes there are several other methods if we experience urgency.