We mean changes. And we mean something unchangeable. We mean something that moves. But against an unmoving background. And vice versa.
Animals can sense changes.
But consciousness of time involves the double sense of constancy and change. Which can only be attributed to those who give expression to it. And that can only be done through language, and only man has language. The perception of time and language are inextricably bound up with each other. Iris Murdoch, Shel Silverstein, Paul Bowles .