An ending watched together gives people a small shared disappointment or satisfaction to carry afterward.

Watching something finish in the same room creates a joint holding. Whatever the last scene delivers, everyone now owns the same reaction and can refer to it for years afterwards without explanation, which is a modest but real form of connection. The quality of the ending barely matters; a bad one bonds people about as well as a good one. What is being made is a shared reference point rather than an opinion.

Finish something with other people rather than alone this month. A series, a match, a long book read in parallel. The talking afterwards is the part that stays.