You're right, it is very simple to say but really hard to follow because we are not committed yet to do it and our mindset is still in doubt and worries. People who can make a long-term holding are the people who can also afford to lose their money in the future. But I know that they never think about it, they have already foreseen what will possibly be happening in the future a reason why they are taking such risk, not for losing but for gaining.
Some do even forget that they had invested and just letting those coins or investment sit for too long and you are right that they are really on that level where they do fixed up their minds that they should hold for long term but there are instances on where you do really changed up some thoughts and might be considering on selling out those investment when you do saw that it is worth to take up some profits.
If you cant hold then doesnt mean that you shouldnt buy because no matter what kind of strategy you've been making, just be sure that you are really making or reaping profits.