When I was in Kansas City a few weeks ago for my high school reunion, I heard a great idea for a book group.

A guy who had moved away from Kansas City had committed to coming home every six weeks or so, to spend time with his parents, who weren’t in great health. (I don’t remember his name, so call him John.)

Some friends who still lived in Kansas City decided to form a “pop-up book group.” They’re a book group that meets only when John comes to town.

I think this is a great idea, for many reasons.

First, I’m a big believer in forming groups as a way to stay closer to friends. It may sound strange to talk about efficiency and friendship, but friendships take time, and most of us don’t have much time. By meeting in a group, you see several friends at once; you cut down on time spent coordinating when to get together; if you miss one meeting, you’ll see everyone the next time.

Second, I’m sure it makes it much more fun for John to visit home. He sees friends, he feels part of the life of Kansas City. That little bit of fun may make it much easier for him to stick to his commitment to visit his parents, over the long run. As my Habits Manifesto argues, “When we give more to ourselves, we can ask more from ourselves.”

Third, I suspect that his parents may also enjoy his involvement in the group. It’s a little less time that he spends with them, true, but he hears news about what people are doing; he has his own independent life in Kansas City, he’s not just a constant visitor. It’s probably more fun to be around him.

Fourth, this is a very nice thing to do for a friend. I’m sure it makes John feel happy that they built the pop-up book group around him, and I’m sure it makes the members of the group feel happy, too.  Few things make us happier than the good we do for other people.

This group happened to form around books. I’m a huge fan of book groups — I’m in four book groups, myself, and they’re a huge engine of happiness for me. Huge.

But a group can be formed around anything.

You could start a Better Than Before group, for people working on their habits together. 

A friend is in a “fine baked goods” group. They take turns making fancy desserts for each other, and while they eat the desserts, they discuss baking.

My father-in-law was in a group (it only met once) where people talked about fly-fishing. They didn’t fish, they just talked about fishing.

Along the same lines, at my daughters’ school, one after-school club is “Sports Talk.” They talk about sports.

A friend told me, “I’d like to start a group where we discuss People magazine. I’d always be prepared, and I have a lot to say.” She still hasn’t started it, but apparently people are clamoring to get in.

Also, a “group” can be small. I’m in a terrific group that has only three members.