I think you need to leave Britain before you can truly understand what it means to be British.
No-one's mentioned sense of humour which is something expats often miss and people of other nationalities comment on. It's not necessarily "better" or "worse" than the SOH of other nationalities, but it is unique and usually a very dominant part of Brit personalities.
If you ask an American, they'll say bad teeth and saying "tally ho".
