"A Horse Walks into a Bar" is a short story by David Grossman that explores themes of humor and existentialism. The narrative centers around a horse that enters a bar, creating an absurd situation that prompts reflection on the nature of life and the human condition. The story uses the horse as a metaphor for the unexpected and the absurdity of everyday life. Through the interactions in the bar, it highlights how people cope with their struggles and the importance of connection, even in the most unlikely circumstances.