Knack is a very important quality which is transmitted via Shards. Actual knowledge, eg. the knowledge of how to speak a language, or the knowledge of how to compute mathematical formulae, etc is not transmitted.
But the Knack is transmitted. This is why so many people have a yearning for something they don't have (maybe they can't have). They don't know where it comes from, they ask themselves, "Why do I feel like I have to do something and I don't know what it is?"
It's because you're not going in the direction that your Shards are trying to pull you in. Depending who your Shards come from will determine what you have a knack for.