We're not absolutely tabula rasa, but as I understand it, what we're born knowing is the absolute basics of instinct: smiles, grasping, breathing, crying, recognition of gender in others, and a desire to make pillow forts.

(Quite why we all seem to go though the "make pillow forts" stage as young kids, I do not know. Predators in the ancestral environment that targeted, IDK, 6-9 year olds?)