There is a kind of knowing that works by suffering because suffering is the appropriate acknowledgement of the way human life, in these cases, is. And in general: to grasp either a love or a tragedy by intellect is not sufficient for having real human knowledge of it.
Nussbaum argues that tragic knowledge is constitutively affective and experiential, not reducible to correct belief, because suffering is the only adequate epistemic response to certain human realities.
, The Fragility of Goodness: Luck and Ethics in Greek Tragedy and Philosophy, 1986thesis