I didn't grow up poor. But I did become a single, teenage parent and was very, very poor then. I had no idea what the fuck I was doing. I'd never learnt to budget, pay bills, save up for anything etc. I had absolutely no financial life experience whatsoever. I made very poor decisions, and even though I'm in my 30s I still haven't financially recovered. No mortage (never had a deposit), poor credit, but this is improving. No access to low interest rates for essential borrowing.
Mostly, I felt incredibly judged as a teen parent. I wanted to provide my children with the life I'd had, but I had no means by which to do so. I had nothing in common with other teen parents, who had grown up in a different social environment. It shaped me more than my actual childhood, those early years of my eldest children.
I've since married, had two further children and due to hard work by myself and my husband, we are now financially secure. We are not rich by any means, but we are comfortable. Our bills are paid, on time, we never worry about where the next meal is coming from anymore and we never go cold at home. We have adequate clothing for all weathers. I can spend money on things that are cheaper long term, but more expensive up front. Bulk buying, getting things when they're discounted because the money is available when we need it to be. My children are all kitted out for school in September already, for instance, because I bought in the M&S discount. I buy M&S partly for the quality, and partly because I want people to know we aren't poor if they see the label at school. I used to feel like the Asda uniform we bought was judged...
I find the fact that I can now choose quality items that last a long time, instead of having to buy cheap things repeatedly (due to their crap quality) an absolute revelation. So I do choose them.
So I'm materialistic because I still bear the absolute fear that those around us all think I'm a shit parent because I was once a (financially) poor parent.