We don't necessarily
love saying it, but it is common in conversation particularly among younger Americans. The phrase "you know" is often inserted unconciously in our speech as a "filler" to allow time for us to formulate our thoughts into spoken words, much like the non-lexical "uh" or "eh" or "um" or "er" that some of us use. The latter collection of vocal pauses in speech are common in casual non-English conversation as well.
Another purpose of "you know" in American conversation is to establish a common connection of knowledge or experience with the listener, much like the interjection of "yeah?" by some British English speakers or "eh?" in Australian English. There are very likely equivalent linguistic hooks in other Western languages, you know?