Let's say you bought a bitcoin for $1000 in January 2018.
So you have to beat inflation and also the performance of other investments to say that your Bitcoin investment was a better investment, than other alternative investments.
Let's say your inflation is 5% and your best return on some other investment is %20 per year, then your Bitcoin price increase will have to be more than %25 to beat the alternative investment.
Let's say you hoard for 5 years, then you would need a price increase of 125% to beat your alternative investment returns over 5 years.
So we cannot have a price increase of 800% in year 1 and then a price decrease of %400 in year 2 and another price decrease of 200% in year 3 and so on...
Hope you get at what I am saying. Hoarding might be harmful to your profits, if you do not cash out SOME profit on the ATH.
..... You might end up with a bitcoin worth $100 in year 5. 
So you have to beat inflation and also the performance of other investments to say that your Bitcoin investment was a better investment, than other alternative investments.
Let's say your inflation is 5% and your best return on some other investment is %20 per year, then your Bitcoin price increase will have to be more than %25 to beat the alternative investment.
Let's say you hoard for 5 years, then you would need a price increase of 125% to beat your alternative investment returns over 5 years.
So we cannot have a price increase of 800% in year 1 and then a price decrease of %400 in year 2 and another price decrease of 200% in year 3 and so on...
Hope you get at what I am saying. Hoarding might be harmful to your profits, if you do not cash out SOME profit on the ATH.
..... You might end up with a bitcoin worth $100 in year 5. That is why holding tokens are not totally adviceable and should be moderated. Many people here are always arguing to hold and hold their tokens for a long time. Problem is that, how long is that time. Like what you have stated holding it for a long time may result to big losses. What we can do is to get use it in a wise manner, make it as an investment not for a long time.