My experience is very similar. My gp's were 2nd generation immigrants on one side and 1st on the other. I was the first to go to college and among only a few who had graduated from HS, or even attended HS. All of gp's were done by the 8th grade, latest. And my father did not graduate. My mother did so by the skin of her teeth.Both gm's were housewives and my gp's drove truck and worked unskilled factory labor, respectively.
I remember my childhood as being very awesome (until I got to be about 11 and for reasons having nothing to do with money). This even though my mother was very young and single at first and my father was absent. I spent a lot of time with my grandparents and lived in the same house with one set for a long time. I remember when my last paternal gp died, she had more than $200,000 in investments. How she managed that when they had a household income that never exceeded $17k per year even into the late 1970's I will never know! Yet she never spent a penny of it she didn't have to, except to spoil me a little. And by that I mean green grapes or strawberries from the market in Winter-NOT a new car. lol
Everything they had was simple but paid for. My grandmother had a hand wringer for the laundry at least until the late-1960's. If it worked, you used it and didn't replace it with something better even if you COULD afford it. She taught me how to braid by pinning three lenths of cloth to the chair. She taught me how to knit and sew and prepare meals from almost nothing. They only went out to eat when I was with them, and it was to IHOP or similar. She would let me stay up late while she watched old movies on the ancient tv and rub my back for periods of time that seemed not humanly possible, even to me back then. I'm saying this only to say that that's what I remember. Not what I didn't have.
Sure, I strayed quite a bit in HS. But I always had that foundation and they never approved my straying. Tacitly or otherwise, although they continued to love me. It's about character in my book. jmo