Holden's desire to be the Catcher in the Rye. In what ways is this ironic for him? Chapter 22

Holden’s fantasy about becoming “the catcher in the rye” is rather abstract and surreal, but it spotlights his desire to preserve what little innocence he believes is left in the world. To him, children represent the purity of youth, but he recognizes that this purity inevitably recedes as they grow older. For this reason, he wants to protect this purity from corruption, and wishes he could spend all of his time keeping the hardships of the adult world at bay. He himself is still quite innocent and immature when it comes to adult matters. “"Anyway, I keep picturing all these little kids playing some game in this big field of rye and all. Thousands of little kids, and nobody's around--nobody big, I mean--except me. And I'm standing on the edge of some crazy cliff. What I have to do, I have to catch everybody if they start to go over the cliff--I mean if they're running and they don't look where they're going I have to come out from somewhere and catch them. That's all I'd do all day. I'd just be the catcher in the rye and all. I know it's crazy, but that's the only thing I'd really like to be. I know it's crazy." “(J.D. Salinger).