Why is this not funny?

Rating: 2/10 (10 July 2018)

Elsewhere on the web I have seen comment saying that people in the USA find the film funnier than UK folk. There seems to be the suggestion that there is a completely different sense of humour between the countries. I do not think this is right. I am from the U.K. and I think there is fabulous comedy from the USA. Great USA comedies from over the years easily spring to mind; Some Like it Hot, Harvey, Nelson Dynamite, Brother Where Art Thou and on and on. When it comes to TV series, Seinfeld, for example, is fantastic. I loved the episode about the English Patient in which "Elaine" voiced precisely what I felt about the film in the funniest way.
But the Hangover neither made me laugh nor smile. I saw no funny wit and no funny slapstick.
Incidentally, I watched a few episodes of Friends recently and noted that there is some terrific slapstick there that I had not picked up on before, often involving "Ross".