Thoses how many *blah blahs* does it take to change a light bulb etc. jokes, i dont get them?

Changing one is a common and important task which everybody should be able to do. Therefore, this universal situation becomes a good platform to make fun of people who can't. I mean of course they can, but then there'd be no joke. Except this arabic loser who wouldn't change a lightbulb in a guest room because he hadn't been shown how. What a fuc*en wanker.