I saw this 1966 British comedy when I was a freshman in college and thought it was the funniest thing I'd ever seen. Thirty years or so later, I saw it again (on VHS?--I can't remember) and was a little disappointed. It didn't seem as funny as I remembered. Recently, now forty-five years on, on a whim I recorded it from TCM and gave it another chance. This time I found it very funny indeed, maybe not as funny as when I was 19, but funnier than when I was fifty.
I don't know what to make of that, but I recommend the movie. It's the sort of nutty thing that some Americans, such as myself, think of when we hear the term "British humor", though the Brits don't seem to do it anymore. It's the story of two brothers who are the last surviving members of a tontine, a sort of lottery in which the last member to die is the winner. One of the brothers wants to kill the other, while the second is a dotty pedant who is oblivious to the whole thing. Both have relatives who have a stake in the outcome, particularly two very greedy and unscrupulous nephews of the oblivious brother.
The plot is complicated and absurd. The cast includes Peter Cook, Dudley Moore, and Peter Sellers, whose verbal play is really the funniest stuff. (Sellers's bits are among the funniest of all, but the fact that some of the humor is based on his trade as an abortionist leaves one a bit queasy.) Also in the cast: Michael Caine, John Mills, and Ralph Richardson as the fact-collecting brother Joseph Finsbury.
It's the sort of thing where a line like "You realize you made me drop my grebe" is hilarious. Or "This must be the effect of the nutmeg tart." Monty Python's humor didn't come out of nowhere.