The education thing, I'm not entirely sure. I've met some real retards now and again, but I will chance it and say UK people will generally be more polite/helpful. But it depends how lucky you are really.
I myself will talk to anyone that's willing to talk to me, and go as far as giving up my seat for the pregnant/elderly/disabled on any form of transport/public place, or even get up and help, say, a mother of 2 carry her shopping onto the bus, and off the bus if they get off before me.
As for the thoughtful thing, OUTSIDE London I'm sure if you're out and about on public transport/waiting for bus/train etc, you can easily strike up a convo with anyone (not chav/not foreign, white, usually). by saying "nice day eh?"
For some bent reason the weather gets anyone talking.

I hate it, but I admit I've used it a lot myself sometimes when there's no escaping conversations. A few times I came home from work in London there would be 2 or 3 willing to talk, but not on the tube but on the proper trains.