I remember the first time in my life when I understood. It was a powerful experience, and a huge shock to my 3- (or maybe 4-) -year-old mental system. I am not sure I ever got over it.
I was busying myself looking at a tear-off calendar - leafing through the pages and looking at numbers and pictures. What are these pictures of? -- I asked someone, most likely my grandmother who spent more time with me than anyone else. It was the Moon, I was told, and the pictures represented the phases of the Moon I saw in the sky.
Once it sunk in, I was filled with horror. I went through the calendar page by page, watching the moon's representation get fatter, become a full circle, then start to wane from the other side until eventually disappearing and starting over.
I couldn't believe it, so I checked again. And I continued paging through the calendar page by page, realizing that each page was a day. Really understanding what's going on. All the way to the end of the year. It's all the same.
The mystery of the world was ripped away from me in one horrible instance. Before, the world was full of random wonders. The sun was shining. The moon was maybe a crescent, or maybe a big round disk hanging low over the horizon. I never considered that anything was connected or sequential before.
I started crying, and no one could understand why. "Same!" I screamed over and over. The world was ridiculous, repeating itself like a broken record. I could not fit it into my tiny mind, much less express it in any meaningful way why it was so upsetting.
The endless time still existed before, but the future was laid on a grid in front of me, the moon repeating its dance; the days, each labeled with a number corresponding to a page soon to be ripped out of the calendar, followed one another in a specific sequence.
I shook in horror. The infinitely fascinating, unknowable world I was counting on collapsed into a predictable and unstoppable, sequential machine built by a sadistic accountant of a god.
My life would never be the same. It would be one day after another, each numbered, with the pre-determined moon. The magic of infinite possibility was gone. I felt old and tired, and cried myself to sleep, because I now knew, and there was no unknowing it.