Even among men lacking all distinction he inevitably stood out as a man lacking more distinction than all the rest, and people who met him were always impressed by how unimpressive he was.
The quote highlights the protagonist's mediocrity, suggesting that he is so unremarkable that he stands out even among others who are also ordinary. This emphasizes a sense of singular dullness that makes him memorable, despite lacking any traits that would typically attract attention or admiration. The idea reflects on how, in a world filled with the mundane, some individuals can still seem exceptionally bland.
This observation provides a commentary on the human condition and the nature of identity, indicating that even those who are forgettable can leave an impression. The irony of being "impressive by being unimpressive" presents a unique take on how people perceive one another, contributing to the overall themes of absurdity and individuality in Heller's work, "Catch-22."