The best metaphor of the nature of time is a game from my childhood that we called "Escondite Inglés" (English Hiding Place). One had to close his eyes and count to 3: "1, 2 y 3, escondite inglés!" The others, who were immobile, took advantage of this interval to move without being seen. The one who was surprised, lost and replaced the other. Well, that's the time: you see that things change but you can't see how they do it. Carmen Martín Gaite wrote a beautiful poem about this interpretation, but more focused on death (one of her daughters died young) "1, 2 y 3 , escondite inglés / a esa niña de rojo / ya no la ves..."