In the good old days of “actually existing Socialism,” every schoolchild was told again and again…

of how Lenin read voraciously, and of his advice to young people: “Learn, learn, and learn!” A classic joke from Socialism produces a nice subversive effect by using this motto in an unexpected context. Marx, Engels, and Lenin were each asked what they preferred, a wife or a mistress. Marx, whose attitude in intimate matters is well known to have been rather conservative, answered “A wife”; Engels, who knew how to enjoy life, answered, of course, “A mistress”; the surprise comes with Lenin, who answered “Both, wife and mistress!” Is he dedicated to a hidden pursuit of excessive sexual pleasures? No, since he quickly explains: “This way, you can tell your mistress that you’re with your wife, and your wife that you are about to visit your mistress …” “And what do you actually do?” “I go to a solitary place and learn, learn, and learn!”

from Zizek's Jokes