Re: People I think should stay away from bitcoin investment.
I once had to urgently pay a €300 utility bill and fortunately there was this site called bitbill.nl (long since defunct) where I paid about 3 bitcoins to settle the bill. That would have been worth a tidy sum of money today. But necessity demanded it and back then (in 2013) only a few people (such as Max Keiser and Rick Falkvigne) figured the price could once be over $100K.
3 Bitcoin for a utility bill? That would have been around $240k in the present. You are basically a tiny version of the pizza guy who paid 10,000 bitcoins for two pizzas. 
Anyway, as you said, in the past, people didn't expect Bitcoin to reach this far. I mean, how could one imagine a newly created digital currency will someday have a price above $100k? It was an unimaginable thing back then because there was a lot of negativity against Bitcoin at that time. Mainstream media was doing its best to show it in a bad light, but despite all that, Bitcoin survived and kept growing over time, and look where it has reached.
Some day in the distant future, some people might be having a similar discussion again, talking about times when Bitcoin was only $79k and people were throwing away their coins because they were crazy.
