" isn't the experience of flow, to be recognized, need the time-distinction? " Possibly, but not necessarily and only after the fact, so we can talk about it. "how can I know my perception changed without some concept of the "before" that changed?"I can see that time is conceptual but I can't see how any change can occur without time." Good one Matheus, .and an opportunity to go deeper... Thanks 😊 Does a single cell organism experience time? From their perspective. A rabbit? A baby? Early humans? I don't think they experience time as we know by comparing before and after. A rabbit just perceives changes and moves. For a baby, there is perceptive body movements, biological changes and rapid learning. Early humans perhaps experienced life according natures movements, day and night, no time necessarily, just change. More work! Cheers, RD