Just on the topic of getting ID'd if you disagree with it then tough it's the law and it happens everywhere. To be fair a bar doesn't have to have a reason to not serve you, but that's another story. I'm 30 and I carry ID, it baffles me when younger folk don't then get arsy when they are refused a drink. Staff in any bar are busy they may have glanced briefly at you and caught your good side. But once the question is asked they are obligated to see it through even if they then realise your fine.