I don't hate it when people don't possess common knowledge. I mean, common sense is one thing - it's surprising to see people not realize that a large pizza is bigger than a medium pizza, even if we suppose that they don't know what a "pizza" is. But many things are commonly known but not really essential facts of life. I don't know what "touche" means, I couldn't pinpoint the US States with 100% accuracy, I probably know 10% or less of the state capitols, and I couldn't tell you much about non-American cultures beyond a shallow understanding. But I'm not an idiot - I just don't care to know those things. I don't see how knowing those things fits into my life priorities at all. I give others the same benefit of the doubt.