Wodehouse on writing

I've been re-reading What Ho! The Best of Wodehouse over the last few weeks, and what a great book it is. There are chapters and short stories in it that are perfect gems of comedy writing. 

Towards the end of the book are some letters he wrote to W. Townend - just a few out of the hundreds he wrote - and one in particular is of interest to writers struggling to get their book to come together. Here is a man who had been writing for decades at this point - he was in his late fifties...