Just 10 bitcoins are enough for your retirement if you are going to retire only after 20 years.
Even only one bitcoin is more than enough after 20 years. But by considering 2036 commodity prices, you may need 10 Bitcoins to lead your rest of life happier.
Why would it be enough? How would you know that BTC will be worth many, many thousands USD per?
Nobody knows where BTC will be in one year, why would it be possible to know what it will be worth in 20? Bitcoin will bring about a revolution but that doesn't mean that Bitcoin won't itself die in the progress. No revolution without its toll in blood. Remember?
Well this is more of an speculation thread than economics, so we can speculate, and I think he is right. But my ideal luck number is 21, because of the fact there are 21 million coins, so you are a "millionthaire" and wealthier in BTC than 99.99% of people in the world.
I agree. Bing part of the 21 million people grup is special, and it's even less than 21 because lots of coins are lost forever. So let's do the math:
1 - (1,000,000/7,000,000,000)
1,000,000 = number of people who can possibly own as many BTC as you. 7,000,000,000 = Global population
If Bitcoin is a big success and it will be, owning 21 Bitcoin MUST put you in a very privileged position in the possible, period, there are no ifs, it's just physics.