If you don't know what FU money is, watch the YouTube video below. Otherwise, skip the video.
FU money is absolutely integral to happiness, in my opinion. For me, I have calculated FU money to be $1000 per month, which requires about $300k in investments.
There are three necessities: (1) shelter, (2) food, and (3) wifi.
Shelter is $500 per month based on the rent on a one bedroom house way out in the country. Food is $400 per month based on the cost of Soylent (or Joylent/Huel/Aussielent depending on where you live). WiFi is $60 per month. Round it up to $1000 per month.
If anything goes wrong, I can just retreat into the country, sip on my Soylent, and slowly work on eCommere.
Right now, of course, I am in the matrix and I am working, but because I have FU money I don't feel the need to be ambitious or to make myself uncomfortable. I am just cruising so that I can grow my passive/investment income so I can earn more than $1000 per month. That being said, I am sort of passive and betaish at work. I am a junior worker so I follow orders from the manager, but it's not too stressful. If things get really bad, I can always try to transfer to a different area, but otherwise I can just leave and live in the country building up or bootstrapping online businesses.