And very posh, upper class people can be extremely friendly and not give a shit about your background - they don't all do it. It's a particular type.
Also agree with this.
You can tell the ones who are desperate to 'prove' they are 'posh,' or upper-middle class, or upper class. They constantly try to impress people with their 'wealth,' and talk about money, their house value, their earnings, the 'expensive' holiday they went on, how their husband has a 'long commute' and his 'mid 5 figure bonus' etc. And they look down on people who have a small house, and an 'unskilled labour' job, and go to Rhyl for their holiday. And they ALWAYS manage to slip into the conversation that they are middle class...
Proper posh, well-off people don't ever talk or brag about ANYthing they have. They muck in with village events, they wear tatty clothes and wellies to muck out the horses, and they will chat to anyone, and they certainly never talk about money or the value of anything they have. It's incredibly vulgar to do that, and makes you look desperate to prove something.
The majority of these type of 'wannabes' are up to their eyeballs in debt.
Have to agree with a few posters though @pukkapad - YOU seem a little desperate for people to know you are 'middle class.'
I just think anyone who is, shouldn't have to SAY they are. When I met a man in my village walking around in old shabby clothes, covered in mud where his dogs had jumped up him, and with muddy wellies where he had been walking around the fields with them, he was just polite and courteous and asked me if I had just moved here. Turns out he was a multi millionaire, from a family of wealthy people, with a huge farm, and 100 acres of land.
Did he walk up to me and say 'hi, I'm Arthur, I am super fucking rich, I have 100 acres of land and a five million pound farm, and I am upper class, so bow down to me!' Nope. He didn't need to prove anything, or announce he is rich and upper class. Saying 'I am solidly middle class' in your OP (and that you went to a 'brilliant' school') makes you look as bad as the people you're slating tbh.