The first thing to do,' said Psmith, 'is to ascertain that such a place as Clapham Common really exists. One has heard of it, of course, but has its existence ever been proved? I think not.
Psmith expresses a humorous skepticism about the existence of Clapham Common, a well-known location in London. He mentions that while people often talk about it, he questions whether it has ever been definitively proven to exist. This suggests a playful approach to common knowledge, highlighting how things can be accepted without question in society.
By raising this point, Psmith introduces a whimsical notion that challenges the assumptions of everyday life. His quizzical attitude reflects a larger theme in P.G. Wodehouse's writing, where characters often engage in witty banter that reveals deeper insights about their world and the absurdities within it.