That's not what the term meant. It meant you had enough money that if you had a job you could say "Fuck you!" to your boss, his boss, the CEO, etc. and then just walk out, never come back, and live pretty well the rest of your life. (Approximately speaking.) That you didn't have to worry about your resume anymore, career, networking, keeping skills up-to-date, you never had to say yes to anything to make a buck only if it interested you, etc. It did not necessarily mean you were saying that to your neighborhood, society, country, family, etc. Indeed it could enable to give more time and energy to those things. Now, what precisely that money amount is varies of course by person, depending on their needs and desires and situation.