Just a word of "advice" at the beginning: Don't watch this film while you're eating. Maybe you wouldn't want to keep your food after the second half of the film!
This film I've seen for the first time as a child. You love Louis de Funès when you're child. He is the best clown you can get. Then you grow older and you think: ah, silly. Then you grow even older and suddenly you see the film again (it's out just now on DVD to celebrate the master's "90th birthday" in the next week) and laugh tears. Yes, the film is silly like so many French comedies, fast, hectic and silly. But still the idea for the script is brilliant and the "message" works today as it did in the 70s.
The most funny thing about the film for a German, though, is the fact that they dubbed more lines than are actually said in the French original. I just realized this with the new DVD. For the first time ever I heard Funès in French and with the subtitles on I wondered after a while why so often there were subtitles but no dialogue. They actually tried to make it even funnier in the German dubbed version with more dialogue when you can't see the lips or when the lips are moved but nothing is said. It came as quite a shock to me. We have weird ways of treating film in this country...
Anyway, this is probably the best film Funès ever did and if you want to see only one of his films, then let it be this one. You won't be disappointed.