Maybe you can count seconds…But who devised that unit? To us people, “time” is when the sun goes down and a day passes. When the Earth revolves around the sun and a year passes. To many of us time is nothing than a simple physical phenomenon someone happened to decide was a linear measure. physical objects do nothing but constantly change their state. Even things that appear to keep the same form are constantly changing. Don’t understand? Take for example an hour glass. We could say that the neck is the present, the top chamber is the future, and the bottom chamber is the past. But what if we turn it upsede down? the grains of sand that represented the past become the future…and the future becomes the past. but lets say someone walks in after you’ve turned it over. There would be no reason to assume that that person knows the grains of sand falling to the bottom were once the past. Need another example? Ok…every physical being that exists “today”; the Earth, the moon, the sun, animals, people, memories, digitally recorded data… if everything were exactly as it was yesterday, then there would be no distinction between”yesterday” and “today”. That…is all time is. Nothing more.