I see your point on holding some space for self-exploration before we cargo cult other's beliefs as our own. A couple counter-thoughts: (1) There is no forming of ego without external influence. I'd much prefer a younger person be influenced by the enthusiasm for life of Feynmann when compared to the thousands of other options. I imagine influence to be a zero-sum game. Better to have it add up to enthusiasm. (2) We see different aspects of a book at different points in our lives. We hear only the questions to which we are capable of finding an answer (partial quote of FN). Rereading books that influence our younger years is a form of self-discovery.