Even at 2% return-- let's say you earned 10m per year in income/interest/investment return off of it-- you'll still owe about 4-5mil in income taxes each year -- that's how people blow the $ is they don't account for the additional costs and income taxes due each year and spend more than they should.
People buy houses or properties and don't account for property taxes, liability insurance, hoa fees, and upkeep costs-- your 10 mil vacation house may cost you 2-5 thousand per month in additional costs
It all adds up when you think you have "unlimited funds"