This paper invites us to reconsider our usual understanding of infancy, no longer as something that passes but as "infantia." The Latin word "infantia," which is not easy to translate, means a lack of speech, a lack of eloquence, and also infancy, babyhood, and dumbness. Drawing on Barbara Cassin's works on the untranslatables, I propose to translate "infantia," starting by not-understanding, and then by taking detours by different texts, in-between languages. Exercising translation allows us to expose ourselves to the differences between languages. The exercise in translation that unfolds will help to challenge some familiar distinctions such as infant/adult and uneducated/educated.