Well I didn't see the full version of this movie until a couple of years ago. I know it from a 1970s cut-down to 18 minutes Super 8mm film version I saw many times,long ago. Those were the days...
We need to work our way through a self-centered and self serving Jerry Lewis. As an earlier comment correctly stated, Jerry Lewis didn't manage to come up with the "not too bright underdog with a golden heart, trying to live the American dream, facing many obstacles but making it in the end" - story, even though this was clearly his idea of the storyline. You can call me names for my next statement: Sylvester Stallone did that thing much better (even though not through a comedy) in his first two "Rocky" movies.
Anyway, this still is a Jerry Lewis classic with many great scenes. Undoubtedly the best being him doing a perfectly-in-sync routine to "Blues in Hoss Flat", as usual impeccably performed by the great Count Basie big band.
Some other material such as the radio that won't stop playing even when smashed to bits has been done much better in 1940s Warner Brothers cartoon shorts.
The two scenes where Morty (Jerry Lewis) meets "living" puppets are rather painful and reminiscent of Charles Chaplin's later work (Limelight etc.) It's in the "crying Clown" tradition and rather out of place in this otherwise funny and inventive movie. The puppets, a little clown and in a later scene a talking female ostrich, magically coming to life (yet obviously performed by rather average puppeteers) in a comedy are the only beings who really understand our "hero"? I'm afraid this is very weak material.
Jerry Lewis also has his "serius" moment in movies like "Cinderfella", and they are totally out of place as well. But that is a classic: a comedian trying to show his (or her) serious side. I will be tolerant and understanding (=forgiving).
If you are a Jerry Lewis fan, "The Errand boy" is a must see in any case. Jerry lewis definitely was (and remains) a great inspiration to contemporary film comedians such as Steve Martin and Jim Carrey.
