I enjoy watching the price of Bitcoin, and unlike the stock market, the price has a direct effect on me.
Since I first got into Bitcoin, its price has increased by four orders of magnitude. If it does this again in the next decade or two... and I don't spend too much of what I've got... I'll be a millionaire. There's my retirement fund. Ha ha!
I was recently wondering why I didn't buy any Bitcoin when it was really cheap. Then I remembered the reason. It wasn't that I was afraid of losing a few dollars, it was because back then the emphasis was on mining it, not buying it. I wasn't interested in mining Bitcoin so I let it pass me by for a few years. Now I wish I'd been smarter.
The first purchase I made with Bitcoin was an ounce of silver (I think it was only one ounce). Now I realize that ounce of silver cost me over $10,000 (at current Bitcoin prices, anyway). Ouch. But back then I suspected Bitcoin might fade away before long, and if I bought precious metals with it, at least I'd have something tangible.
Multiple times I would wait until my dollar balance increased enough that I felt I had some extra, then buy more metals. And I once bought someone a gift with it-- just before the price of Bitcoin took a big tumble. I was pleased with myself that day, but even that "high" was when Bitcoin was less than half what it costs now.
I have a little (OK, a lot) buyer's remorse over the things I spent Bitcoin on. There's only one thing I might still consider spending some Bitcoin on, but haven't decided whether it would ever really be worth it to me. I don't want to feel that regret again. And, at the moment I barely have enough Bitcoin to do it anyway.
Somewhere out there right now is the "next Bitcoin"-- an opportunity to spend a tiny bit of money today for a huge payoff in a few years. But I don't know what it is, and I doubt I'd trust anyone who said they knew. Not that anyone would have ill-intent, just that the future is too uncertain.
I regret not getting Bitcoin sooner, but I'm really glad I got into it when I did instead of only getting started now.