As for all the great people that have lived and been born in this country there must be somethng about it that makes it's people that way. The fact so many great inventors were born here can't be coincidence. Charles Babbage and his difference engine and later Alan Turing who invented the first computer (which the Americans later stole) and despite what American movies teach you he created the computer that cracked the Enigma code (again not an American idea).
We have a great (ha, relatively) education system, and for that I am thankful, but not proud.
If Alan Turing was German he would have fought for the Germans because he would have grown up with a national pride for that country. Without his work the war could have ended differently, so the fact he had national pride himself to help fight the war for the English has had a direct influence on the country you are living in today whether you were impacted by it directly or not. The same goes for all the pilots that died for you and me in the Battle of Britain, that in one voice said no to German occupation beacuse they loved the country for what it was and not what it could have become, as well as a million other examples.
Alan Turing and the pilots of the Battle of Britain were fighting, whether they knew it or not, for ideals. It just so happened that those ideals were packaged as an easy to swallow pill by the media of the time - "Britain". Were any of them actually fighting for the island itself? That would be pretty silly...
Now if they are fighting for ideals, does it make any sense to be proud of them just because we share the same or similar ideals? Should we be proud when our ideals spread? Glad maybe, but not proud unless we are the ones spreading them.
If the world was all the same then what culture would you like the whole world to adopt? out of curiosity.
It is immaterial just so long as it enshrines human rights above all else.
If England won the world cup would you really not care even a little bit?
Nope. Maybe I'd be glad of the stimulation the economy would receive? I don't know.
It has nothing to do with me but I will still be cheering on all the British athletes at next years olympics because they represent my county and therefore me.
No they don't. They represent themselves. The only thing that has got them where they are is personal talent and luck (so arguably just luck). The ground they were born on may have been instrumental, but not because it is labelled British. It is instrumental because it magically gave them superior rights to nurturing and education and training than another piece of ground in Africa. Those people don't represent you. You don't have anything in common except that you've been through broadly the same system and they're doing better than you in their field. It's reflected glory at best.
Greatcarbuncle, I think you put yourself down a bit. I'm sure you have contributed to society in some way. Even if it's just helping others, or voting, or remembering and honouring various achievements and sacrifices, you're keeping alive a legacy.
Actually our society won't let me vote yet

but sure, you're talking about individual achievements. Of course I can be proud of myself for making an informed voting decision and I am proud of myself for the voluntary work I do, but am I proud of Normans for conquering England and making a massive impact on the country's heritage and, eventually down the line, me? No.