Happiness is explicitly discussed both in "Raise High the Roof Beam, Carpenters" and in "Seymour: an Introduction." In the first story, Seymour Glass fails to show up at his wedding and claims that he is "too happy" to get married. Here, happiness is contrasted with Zen-like calm and acceptance. To live a truly spiritual life, Seymour believes he needs to maintain a degree of detachment – something that, it seems, his marriage would disrupt. (This idea of detachment is further explored in Salinger's short story " Teddy," if you're interested.) In "Seymour," narrator Buddy Glass claims to be an ecstatically happy writer, a fact that further complicates his attempt to accurately and completely portray his brother Seymour via the written word.
Buddy is lying when he claims to be happy in "Seymour: an Introduction."
Buddy is genuinely, as he claims, ecstatically happy as he narrates "Seymour: an Introduction."