About 7 months ago, I decided it wasn't right for me not know some martial art. I passed a Brazilian Jiu-Jitsu sign while driving one day, and hurried in to sign up.
They meet throughout the week, and like any group, they help each other practice and chat a bit after class. They all know each other well from practice, and all of them are good buddies to have around. There's a courteous, yet casual attitude about them –all mixed with the will to fight and compete. The only tension within the group is the occasional trouble-maker who stirs up drama wherever he goes. They never stay around for too long though.
I fit in with this group because we share values and attitudes, and I've only been in-tune with a couple communities before. Most of my friends so far have much different views than me regarding life and people, and it's hard to feel totally comfortable in those groups. Also, whenever I participated in something athletic, my team-mates and coaches were always very serious about the sport (either that, or they didn't care at all). So now it's really nice to find people who are easy to talk to and competitive, without being aggressive or high-strung.