A person, for example, reads in adulthood a book that is important for him, and it makes him say, "How could I have lived without reading it!" and also, "What a pity I did not read it in my youth!" Well, these statements do not have much meaning, especially the second, because after he has read that book, his life becomes the life of a person who has read that book, and it is of little importance whether he read it early or late, because now his life before that reading also assumes a form shaped by that reading.
