But this is arbitrary.
Let's look at the Aymaras, a people from the Andean region of South America: they see the association between time and space in a different way.
In Aymara, the word “nayra” means past but also ahead, in sight. And the word “team”, which means future, also indicates behind.
In other words, in Aymara language the past is ahead and the future behind. We know this reflects their way of thinking, because they express this relationship with the body as well. The Aymara extend their arms back when referring to the future, and forward when referring to the past. Although, a priori, this sounds strange to us, when they explain it it seems so reasonable that we want to change everything; they say that the past is the only thing we know, what the eyes see, and is therefore ahead.
The future is the unknown, what the eyes do not know, and that is why it is behind us. The flow of time, for the Aymaras, follows going backwards, and with that the uncertain, the future, becomes the report of the past, fully visible.