Knowledge is what makes us different from others animals, because it all deals with our mind and soul only – it's nothing concrete, even though some jobs are based on it; it's nothing to be eaten/drunk or to sleep in or to cover with, but we just aren't humans without it.
Of course it's a choice, not a duty, everyone is completely free to decide not to have knowledge (that's one of the meanings of freedom); however never forget people's ignorance is weakness to people theirslves and power to overbearing potents.