My revelation of late is about the "Enoughness" concept in YMOYL. Having needs, wants, and even small luxuries met, with "Enough" being at the peak of a bell curve.
I can relate to this, but I'm coming from the other side of the bell curve:
I grew up in a family that never had "enough". By that, I mean, our actual needs went unmet or were delayed. I specifically remember saving "good cardboard" to cut into shoe-shapes when the shoes wore holes in the soles. I remember being on a "rotation" for new eye glasses. I remember all 5 of us kids having strep throat, and sharing 3 bottles of medicine among us. I remember wearing too-short jeans to school. I remember having no lunch and laughing it off, claiming I was dieting. I remember going to bed early because it was just so cold in the house. I remember a winter with no hot water.
In late high school I realized that much of the above was caused by my parents' lack of money-management skills, so in college I spent time every week in the library reading: Reading about frugal living, reading about investments, reading about 401Ks, reading about all sorts of things. I couldn't put them into practice yet, but I learned how to do it once I actually had some money.
Still, it was something of a surprise to me when I reached the point that I could have "enough" and still be comfortable, even have enough to save. On some level, I had some financial double-think going on: I expected to work and do well, yet I somehow couldn't imagine ever having ... excess. I thought saving would be a sacrifice, that I'd be able to save by continuing to skip lunches and wear shoes with holes in the sole. 18 year old me would not have believed how well I've done.