Great thread.
I learnt that not all middle class people vote Tory and not all working class vote Labour. Took me a surprising amount of time to learn this.
I grew up in a family with little money until I was about 8. Then suddenly we had more and I was maybe one of the first to get a bidet, shower and dishwasher installed.
I wasn't nurtured or valued/respected as a kid - often went unscathed to school with dirty and smelly clothes. But our house was immaculate. Friends would be confused and surprised between the state of me and our house.
Now my parents are extremely affluent but their attitudes towards refugees, for example, are a disgrace. I sometimes feel ashamed of them and we aren't close.
I remember asking my best friend why she didnt get a Walkman for xmas. I couldn't understand why she hadn't, they were so cheap. I went over and said about everything I'd got, not being mean, just didn't get it. I still feel terrible about this. 
When I was in my early 20s and started drinking wine rather than cider and spirits I remember loudly complaining that my wine wasnt sufficiently chilled - it was red! 
caused much amusement! I remember thinking it very posh if someone had a home with more than one loo! Now it's the norm in our circles- although we don't.
Now I would say my family - dh, kids and I are middle class. We have very little disposable income, but spend it on music lessons and gym classes etc. We drive an old banger but go out for food w kids occasionally. We tend to have little treats and maybe indulge on a weekly basis rather than saving it for expensive holidays for example.