No offense, but it seems it just the same as investing in "rocks"
You'll never use them.
Isn't gold a kind of rock?
I mean normal rock, that you can find anywhere, everywhere, and anytime.

Why would someone just buy bitcoin and then hold it forever, doesn't care about prices, even it hits more than $1000000~ or lower than $0, and still hold it?
If you cared to read, you would have seen that I mentioned that I would hold onto a part of it, not that I will hold all forever. It would be the most prudent decision.