I've just come back from 2 months working in Germany. As a privileged white westerner, I'd never experienced racism until I got there. I had doors slammed in my face, was sworn at, my UK plate car was routinely the subject of agressive driving and I felt unwelcome and was extremely glad to leave (I chose not to extend my contract because of the problems I had).
Now, I've worked internationally for many years, so I know what is cultural difference and what isn't. This was genuine racism.
It has given me a very welcome perspective on what it must be like for people to live in the UK and be the victims of racism. Personally, I've always welcomed other cultures, and been pleased that they've chosen our country to live in. I mean, honestly, what a compliment!
In my case, I was only in Germany for 2 months so couldn't possibly have assimilated the culture and learnt fluent German (although I did actually study it for 5 years, so I wasn't quite the philistine they thought I was).
I do think however, that to get the most out of living in another country, and this is from personal experience, you should attempt to learn the language and make friends outside of your local community.
I don't think this actually translates as non-British people converting to British living though. I'd feel terrible if we forced all non-nationals to ditch their traditional clothes, wear shell suits and eat burgers. Embrace other peoples differences - otherwise shouldn't we stop having curry as our national dish??