Now I understand more better why 4 years is considered as long term for holding bitcoin investment. I had never considered age and health as a factor that could influence how long some investors could hold their bitcoin. And you are absolutely right, because an old investor who is already 80-90 years old wouldn't want to hold his investment for as long as 20 years, because at that age such investor could die at any time due to his age. So in essence people that fall into this category tends to hold bitcoin on a shorter duration. So you people who are fit and still have a reasonable number of years ahead of them should be the ones holding bitcoin from 10 years and above to actually see more profit from their investment.
Well, if you invest in real estate or property, four years is considered a very minimal period as people would buy property for a decade or more and will always want to hold for as long as possible. The same goes for Gold and other investments, but when we talk about bitcoin investments, people find it hard to hold 4 years and that is considered as a very long time. I find this behavior very strange and the reason for this is that it is expected that bitcoin and crypto investments give a lot more return in quick time, that may not be possible in reality.