Football and other obsessions

I was thinking about a friend of mine and about the nature of obsession.
It is funny how we as people and as individuals can become so obsessed about something so quickly and SNAP! Just like that the object of that obsession can become our one and only focus.
Some people become obsessed over a sport like football. When Bill Shankly wrote "Some people think football is a matter of life and death. I don't like that attitude. I can assure them it is much more serious than that." he wasn't kidding... to some men football is everything they could ever want.
To others, finding that special person is what its all about. Some do take it to the extreme though and spend every minute of the day obsessing about that special him or her - to the point where it becomes an unhealthy form of behavior. We all know someone who's been stalked or has been involved with someone who did not know when enough was enough.
Other times obsession can be a good thing. Look at this new project going on at Niagara Falls - a giant drill that is about to begin a historic undertaking by drilling a 10 km tunnel through solid rock in order to provide a new way to generate clean electricity for Ontario residents. Pretty impressive eh? I'd bet any money that behind this project, behind the planning and preparation is at least one person who is and likely has been for some time absolutely obsessed with making this project a reality. Without this person and this obsession, this project would have died a quiet death some time ago...
The same can be said for any musician who has dedicated his or her life to their music... or to any environmentalist who has dedicated themselves to a cause they believed in...
John Irving wrote in his book Hotel New Hampshire that the secret to a happy life was to "get obsessed and stay obsessed".
Is he right? Is obsession a necessary evil in which we as people can immerse and lose ourselves?
Do we need to find an obsession in order to be truly happy?
Do we need to lose ourselves in something in order to find ourselves?

Comments on the question of obsession are invited.
Just don't get obsessed about it...