Third places. Become a regular at game night, church (if you're into that), join a bowling league, join organized dinners through meetup.com or whatever the modern version is, take up martial arts, take adult education classes outside your existing interests. There are more options out there than ever before.

Read "Surely You're Joking, Mr. Feinman" and really absorb the part where he explains how he had so many crazy adventures and encounters.