X-rated Bob wrote
I find the intensity quite interesting. They will let nothing divert them from a match. The United supporter mopes for days if his team loses and goes through exaggerated and extravagant emotions when watching a game on TV. I don't know whether to worry about the over-done weird intensity of it all or to envy them for having something they feel that passionate about.
I'm exactly the same - but about Liverpool FC - and with the same absence of any genealogical connection. In my case it goes back to being a football loving youngster in the late 70s in South Africa. Firstly, ostracised at school for playing football for the town team (as opposed to rugby for the school team) on Saturdays. At an Afrikaans medium school (who would under no circumstances have a football team) this was original sin in those days! So playing football was actually part of the counter-culture (along to listening to Satanic (!) ROCK music) in my community! Add to this the fact that in 70s South Africa football (or 'soccer') was also viewed as a game for 'the others' as opposed to rugby as the game for the whites, it added another dimension where football was regarded as a game for either non-whites or 'Souties' ('Englishmen').
So there was a very distinct cultural dynamic around this thing - at least in the parts where I grew up. Every aspiring football player needs a team and heroes to support and aspire to. But we were culturally and politically locked out from having South African heroes. Remember that television only started in SA in about 1975. You would hear stories of impossibly talented local players like 'Ace' Ntsoloenga and "Teenage' Dladla, etc, but never get to see them! So when television came to SA, the only football you saw - once a year - was the FA Cup Final! This was an annual mega-event with all the players at the local football club staying behind in the club-house, watching and drinking, etc. We got to know these teams and waited a year to see them play live again! By hanging around with the English kids at the club we also got hold of copies of 'Shoot' and other UK footie mags I can't even recall now - sow that was the glamour and reality of our football experience. Opened up the world of 'Roy of the Rovers', 'Johnny Cougar', 'Billy's Boots', etc - wow, I'm reminiscing now :-[. Every player at the club literally, and gradually, latched on to their favourite UK team that became 'your' team as if you lived there - and you'd defend it till the death.
So it was a weird process for me. That's why I've been as passionate a LFC supporter as any other since the late 70s. It's 'my' team and will never be deserted - not even by this humiliating clinching of a 19th title by the old enemy. All hail the return of King Kenny!!! ?
As to why the younger generation are so passionate about foreign teams,I can't say. This was only my personal experience. But the fact that Man U, LFC, etc are so huge all over the world (merchandising, broadcasting, etc) must mean that there is another powerful dynamic drawing people from across the globe to these high-profile teams.