"The trick is that you condition yourself: I'm only getting paid (X dollars) a month, and you have to live with this," he said.
Simply put, I can't imagine thinking "I have to live on less than this x dollars." I buy what I need, a few luxuries, make sure things that I buy are worthwhile, etc. and I always spend less than a 1/3 of what I make.
My portfolio can provide X dollars per month, where X is around $3000 or $3500. I typically spend much less, probably closer to $1.5-2k/month unless some large lumpy expense comes up. So getting used to having max potential spending of 50-100% your typical spending isn't necessarily too hard to live with, and allows for needs, wants, and some pure luxuries. I like to say I can have anything I want, but not everything I want. (As long as "anything" doesn't cost more than $35-40k/yr).