I grew up thinking I was middle class, I guess I was if you accept the bullshit definition of class that most people eat up these days. What I meant by middle class was things like behavioural norms, an accent, tastes in music and clothing etc. Now A) as an adult alot of it just feels like its too much effort and B) I can't define myself as middle class anymore because I see it as a deliberate attempt to blur the lines and make the whole question of class come down to something that is barely more than a lifestyle choice.
Class is structural, it is primarily about your relation to power, both political and economic. Roughly 1% of society run things politically and economically, the other 99%, weather they want to pretend to be something else or not, do not. The rest of us are proven to have no impact on our government, we have to rent ourselves out to those who have money to gain access to resources to survive, most of us have to pay just to live somewhere (either repaying a loan or paying a landlord) etc. The 1% on the other hand are the ones who buy us, who reap the profits of our labour and pocket much of what we are taxed and they make all the decisions.
There is a very signifiant amount of practical lifestyle difference between a reasonably skilled professional in the UK who earns comfortable wages and goes on holiday and has some nice things and an unskilled Latin American working in a factory to survive on poverty wages but that isn't the point, its only when we realise that fundamentally we're all in the same position that we see that the fate of the 99%/ working class/ have nots/ lower class or whatever we're calling ourselves is bound together, we want the best for each other because it afects all of us.