Thanks for the ideas everyone!
From my own thoughts, I believe it's something to do with memory. Let me clarify.
I remember what happened at tennis yesterday, but when I think back to it, the pictures are discontinues, and also many gaps (e.g a missing arm of someone, a chair that lost one leg, a missing part on a wall etc)(because the observer cannot capture all events happened at that point of time)to travel back there.
And let's assume that we do travel back with missing parts, the physical reality would be
disastrous, the material world would be incomplete. So consequently we cannot travel back at all.
But from you guys' interpretations, time (and space) is a continuum (single entity) so yesterday, tommorow and all points in time already exist, so yesterday is only forgotten (like tinytree said), but not destroyed. However this leads to another question, if yesterday is a thought, how can we destroy it?
