Some people just make you sick.
"I can do anything!" "Everyone loves me!" "I'm rich!" - these are just a few examples of what people think and say about themselves when they are grosskotzig. But their self-awareness is far removed from reality. A Grosskotz is almost always viewed differently by others. Their bravado rankles, their narcissism grates, making them difficult to warm to.
Kotzen is the German colloquial word meaning "to vomit." But - surprisingly, perhaps - that has nothing to do with the origins of grosskotzen. The word most likely stems from the Yiddish grosskozen, which refers to a very rich man or a poser. But the word could also derive from the local dialect spoken in Berlin. There, a Grosskotz is someone who spits far into the distance. So, those hoping to make friends should avoid acting like a Grosskotz and avoid making too many loud boasts - and spitting, too.