I'm from the UK and have spent the past two winters in Canada, granted I was into American football beforehand, but being out in North America, being able to watch the games at a reasonable hour, was amazing.
I absolutely love it, so much so that on my way out west to BC in November I detoured through north Florida to watch Florida v Florida State and Jags v Texans. (Flights were a bitch! Manchester - Orlando - Jacksonville - Atlanta - Seattle - Kelowna) I'm not a fan of any of these teams but it was unreal just to see some games live in the flesh in their homeland. (Been to most of the wembley games here in the UK, they're obviously great, but not the same as the real thing amongst home fans etc)
I'm lucky to have some great mates back home who are into it to and the people I lived with were into it as well (bar the girls, who celevbrated having sundays back after the superb owl) meaning that I always get a chance to watch it with friends, slating and abusing each others respective teams.
Football is great, not gonna say its better than football or rugby etc, because they are all different with their own merits and frankly I'm a fan of them all. But the thing about the NFL is that its just so freaking explosive, vicious, brutal yet at the same time these massive men have unbelievable skills (great hands, ballerina feet etc) and well I don't really know how to describe it, so I won't but its just fucking amazing.
Anyways, if you don't like it, no one can force you, enjoy it or don't, at the end o the day, its not like skiing, where if you don't like it, you need your head testing.