Jokes like that always remind me of Henny Youngman who had a whole string of them he would unleash. A couple of my favorites were:
'The secret to a long and happy marriage is at least four weeks of vacation a year. She takes her's at the end of the summer while I take mine in the spring.'
'I have had 6 wonderful years with my wife.... spread across 35 years of marriage.'
And by the way, Youngman was married to the same woman all of his adult life and by all accounts, it was a very happy marriage.
Brian