What are some modern day investments that you think could end up like Bitcoin or Ethereum someday, but are currently cheap to buy in?
As for Apple, everyone in the world would have told you it was a losing bet in 1998. You would have been a moron to buy it at that point, it was a year from collapse at best. The fact that it exploded back into prominence and relevance to become the behemoth it is today was totally unpredictable, and realistically you wouldn't have a snowball's chance in hell of picking "the next Apple".
It's utterly unpredictable. There are literally thousands individual of stocks that were once cheap, most of them completely unknown companies, businesses or markets. Spread your money around and you'll win some (and lose some).
The other problem is "getting out". It's one thing thing to catch lightning in a bottle, but a whole other to pull the trigger and sell to capture your gains. FOMO and all that.
> Never invest more than you can afford to lose.
A constant regret of having only bought/mined X instead of 1000*X.
Seriously, back when i first heard about Bitcoin, they seemed almost like a joke. I mined a bunch (difficulty was still in two digits, you could do it on a CPU. There was a button in the Bitcoin Client called "Generate") just in case they would be worth something in the future (it looked like a neat joke after all), but quickly lost interest...
Thing is, such opportunities are often only apparent in hindsight. So, either you know a certain industry well enough to spot something unusual and bet on it, or go the VC route and bet a little on everything that sounds kinda promising.
Of course you can invest in Google which claims to be an AI company, but it is already not cheap to buy.