It's interesting, how time seems to be so elastic; I can have almost no recollection of long, long stretches of time sometimes, while sometimes, so many things seem to have happened in such short spaces of time that I wonder if certain days have more hours than the rest.
Time becomes so terribly stretched when the transition between days--the boundary markers formed by decent hours of sleep--are removed. Then, time seems to stand still yet fly by so quickly, and so many things seem to happen at the same time, that I'm simply left standing, breathless.
Those are what people commonly refer to as memorable times, I suppose.