Being an american in the UK, I find that half of the time I am still trying to work out what has been said, still working out the accent, the different language, etc. and then the topic has moved on!
Of course I can't claim such an excuse when I am reading!
To prove your point, a serious reply. The sense of humor is different, entirely. But we do get it and enjoy it.
Finish the joke- ...an aikidoka walks into a bar and........