I got 2 min in the vid, with proper management you can pimp that currency exchange forever.
For example, you work hard for 15-20 years save $2M in assets. Invest those assets in S&P 500 (averages 10% return) while living on 5% yearly ($100K) how do you go broke? Go see how many Bhat you get for your $100K, and you give yourself a pay raise in a few years when your $2M grows to $3M and you're still taking 5% because 5% of 3M = $150K/yearly.