Why does the name Jack features in so many words and phrases?
jack of clubs/diamonds etc, jack (for your car), jack of all trades, jackass, jackshit, you don’t know jack, headphone jack, jack off, applejack, hijack (carjack etc.), jackknife, jackhammer, lumberjack, steeplejack etc.
It’s no coincidence that the name is so common. By about the 16th century, the name had become so common in fact, that it came to be synonymous with man, or young man in general, and then particularly a generic, run-of-the-mill male peasant. So many job title replaced the word man with jack (steeplejack, lumberjack). Male animals included the name in their names (jackass), those cheeky young knaves on playing cards became jacks, affordable knives became jackknives, and that little chap who helps you with your car is a jack (from which we get hijack, carjack and so on, and the use of the verb to lift to mean to steal). Saying someone doesn’t know shit is bad enough, but telling them that they don’t even know generic everyday jackshit is even worse.
I don’t know how you might feel about the ubiquity of Jack if that’s your name, or nickname. Personally, I’d be proud that my name has had such an impact on the language. I’m still waiting for to niall to become a verb.