interest in bitcoin can completely evaporate, and the same is true for gold.
you needed to hear it, so there it is. having more bitcoin than you need isn't for you, owning bitcoin when you don't need it isn't for you.
the reasons people own bitcoin are all of the reasons people own gold and more. it inherits the same sentiment and does it better. do with that what you will.
just remember that the oft cited tulip bubble and the beanie baby bubble are not examples of irrational behavior. Tulips was a derivatives contract discrepancy that ended in a few months after the bubonic plague killed the traders, the spot market was unaffected and we dont know what would have otherwise happened. Beanie babies had accurate proce information from expected permanent supply chain failure, which ended from a surprise supply increase flooding the market. Only the equities bubbles were irrational.