For many years, I've had a saying that goes something like this: "It's one thing to think you know everything, it's quite another when you actually do." I use this when referring to people who present themselves as larger-than-life know-it-alls (actors, writers, other people with talent) who come off as pompous but who really are as good as they think they are.
Probably the first time I used this phrase was in referring to the "boy wonder" of radio, theater and cinema: Orson Welles (pictured) -- one of the very few creative talents of the 1930s and 1940s who was all those things he said about himself and so much more.
It's hard to argue the perfection of his first film "Citizen Kane" (1941) -- especially once you become familiar with the history of the period, the story behind the movie (William Randolph Hearst and Marion Davies) and the fury this film caused in Hollywood. You don't piss off that many people with a single movie unless you've done something pretty amazing with it. (It has since come to be considered the most perfect example of filmmaking in the 20th century.) In his later years, he began to believe too much of his own blustery puffery and started down a long path toward creative oblivion; but there was a window when he was brilliant and we are lucky so much of his creative output from that time survives.
As you know, I'm a huge fan of vintage radio comedy and drama (especially from the 1930s and 1940s); one of my favorites being (arguably the best of the lot) "The Jack Benny Show." Recently, I've been listening to a group of episodes from March and April 1943 -- a period of weeks when Benny did not appear owing to his severe illness. (On the show they refer to the illness as a cold, but it seems he actually got a very bad case of pneumonia from touring the military camps with his show.)
Welles was asked to appear on the show in place of Benny in what became one of the greatest examples of radio work in all the annals of broadcasting. In these four consecutive episodes, Welles is presented as a character who is all the things people said about him derisively: vain, perfect, multi-talented, perfectionist, know it all. I doubt Welles was really like this (just as Benny himself wasn't a penny pincher in real life); but the Welles character created in these episodes is brilliantly funny. (And all the other regulars in the cast rise to the occasion and are fantastic.)
Here are links to all four of these episodes so you can hear how the character is introduced and then how his pomposity builds and builds. It's a tribute to the talented writers (Ed Beloin and Bill Morrow, in their last year with Benny) who were able to take his temporary loss and create some fantastic episodes of comedy.