Time is an abstraction, not an object, so is compared to space by people all over the world, yet in different ways. Past is ‘behind’ us, future is ‘in front’... English put past on the left, Arabic speakers put past on the right, Mandarin speakers put past on the bottom. Reasoning by metaphors like this can mislead as well as illuminate.
James Gorman, in the Tuesday June 27 N.Y. Times, now notes a fascinating article by Núñez and Sweetser: With the Future Behind Them: Convergent Evidence From Aymara Language and Gesture in the Crosslinguistic Comparison of Spatial Construals of Time, Cognitive Science 30 (2006) 401–450.
Now it appears that speakers of the Indian language of the high Andes, Aymara, see the future as behind them and the past as ahead of them. They gesture ahead of themselves when remembering things past, and backward when talking about the future. Aymara speakers see the difference between what is known and not known as paramount, and what is known is what you see in front of you, with your own eyes. The past is known, so it lies ahead of you. The future is unknown, so it lies behind you, where you can't see. Gorman wonders "Is it possible that human concepts of time can vary this much because of language and culture? And what would it be like to think this way? Do I have the rest of my life behind me? And how can I let bygones be bygones if they're right in front of me?"