I know that if you are into an interesting activity time seems to pass very quickly, whereas the opposite happens when you're bored, but that's not what I'm asking.
Imagine conducting an experiment with two individuals whose job is to pay attention to how fast seconds go by using a clock. It's almost certain that if both people pay rigorous attention to the clock then their perception of "1 second" is bound to be more or less the same and we'll accept this as a fact.
However, since the world around us, and how fast or slow it is changing, is only a product of each individual's perception, is it possible that the perception of seconds for individual A is completely different from that of individual B, but since individual B is a part of A's world, each is consistent for the other?
For example, imagine that A has in mind a specific "duration" for 1 second, but A's 1 second can be B's entire lifetime, if A's perception of seconds is extremely "slowed down". I'm aware that this example holds only with the assumption that somehow A could feel how B feels and perceives the world, but is it possible?
EDIT: this question can be asked about space too. What if each individual's perception of space is different but because everything in this world is a product of one's senses, his "experience" is consistent with that of other human beings. What if a line in my world is a parabola in yours? What if everything through "your eyes" makes completely no sense to me?