Second with boardgaming. Regularly playing competitive games in a friendly atmosphere can lead to new friendships in your 40s, as I have found out. Boardgaming can satisfy the three conditions for making new friends: ". . . proximity; repeated, unplanned interactions; and a setting that encourages people to let their guard down and confide in each other."

See https://www.nytimes.com/2012/07/15/fashion/the-challenge-of-...