the discrete nature of change:
if change involves a difference in state, in that something becomes something else, any absolute difference, no matter how seemingly little, is still a change, and therefore change could be considered as discrete, for there is no "in between" as such. mathematical theory has its concepts of the infinitesimal or infinitely small or little, and of continuous numbers, however these things may not have a basis in reality, they are too abstract!
if, as explained before, all things that exist in this reality, fixed in absolute and relative position to each other in space, could be divided into least bits of matter, each uniform across its volume in space, then each experiences discrete changes uniformly.
the mind and therefore the thinker is quite capable of thinking about things that may not be true. this is the peril of thought. the thinker may not notice change when there are very little differences in state. big changes catch our attention, this is what discrete change seems, after all.