My dad did not laugh once during the entire movie. In fact, during the "killer rabbit" scene, he leaned over towards me and whispered, "This is stupid." Meanwhile, the rest of the theater is in stitches. It's not that he didn't get British humour, because at home he would laugh his ass off at Benny Hill. But Benny Hill was all pratfalls and boobies. There is certainly a lot of what passes for comedy these days that I do not find funny. Funny to me is the Marx Brothers, Mel Brooks, Woody Allen (especially his early, funny films.) I've also enjoyed the whole Judd Apatow/Seth Rogen/Jason Segel/Paul Rudd miasma that's been happening over the last few years.
So, here is the funny "killer rabbit" scene from "Monty Python and the Holy Grail." Or maybe it's just stupid.