I've got to know a few people through Tolkien, and this obsession has also improved a few realtionships. I remember my brother used to pick on me a lot until I had nicked his books and got into LotR soon after he did. He used to whinge if he had to share bunks with me on holiday and he wouldn't speak to me most of the time because I was just a pain, being a little sister. But then we ended up having something in common. He still wouldn't let me join in when he had his mates round to play D&D though.
At work there are always a few people who you don't get along well with, or who you simply don't speak to much. But when you find out that they also love Tolkien you end up getting along really well - that's happened to me a fair few times.