On the contrary, you can quite easily identify people's class independant of their income. With people working in the same job, you can pick out the ones who came from working class backgrounds, because they tend to maintain the accents and colloquialisms from their youth, while those who came from what were middle class families prior to 1970 will speak with plummier accents and generally use fewer swearwords, tending to hold themselves straighter. Those aspiring to middle class status will often look with some disdain on working class pastimes, while those who have been brought up working class will not be aware that their pastimes would be considered as such. If you are aware of these subtle differences, usually unique to the British class system, you can exploit them for your own benefit.
I love how you seem to imagine that working class people spend their free time wearing flat caps and stuffing ferrets down their trousers.
(Actually, everyone I know whether rich or poor seems to have the same two hobbies: going to the pub, and playing video games.)
I don't actually know of any genuine, real-world benefits that come from being "posh", other than being more accepted by other posh people. Since "common" people tend not to like "posh" people so much, that wouldn't be seen as much of a benefit to either.
In terms of middle class pasttimes, well, I'm trying to think of some. You've already told me that everyone who has to work is working class, so that makes everybody I know working class. Every person I know likes going to the cinema, so that's obviously a working-class pasttime. By your definition, I'm practically rolling around in the muck, yet I've been known to attend the odd classical concert and particularly enjoy visiting museums and looking at paintings, so those must be working-class pasttimes, too. I suppose bowling is quite a working-class hobby, but the last time I went I was on a team with a finance administrator, an IT manager, and a renowned academic, so I suppose even you would agree that the last two are "middle class", even though they need to work to pay the mortgages on their five-bedroom townhouses.
Every person I know changes their voice depending on who they're talking to, so accent alone wouldn't give the game away. I spot regional colloquialisms in even my most well-bred friends. The ones who swear the most are almost without exception the ones with the most education.
http://fc09.deviantart.net/fs49/f/2009/195/c/c/No_invitation_by_humon.jpg ^_^
:lmao: