Why didn't C.S. Lewis convert to Catholicism?

This might seem like a weird question if you're a Protestant and really like C.S. Lewis . But as a Catholic, I don't see him as ever espousing particularly non-Catholic positions, and he is very well read at Catholic universities. His faith journey closely parallels G.K. Chesterton , although Lewis came from a more intellectual background. Chesterton converted from nothing to Anglicanism to Catholicism, but Lewis never made the final jump. I read Lewis's book *The Pilgrim's Regress ,* and understand that he had a few things to say about Catholics. But in general, we like him, so why didn't he like us? One of his best friends, J.R.R. Tolkien (who was largely responsible for his conversion), was Catholic, so what made Lewis not Catholic?