I have come back from week long international trips, having arrived by plane on Monday or Tuesday, and by Thursday someone will ask me what I did last weekend, and I'll draw a blank, and the social pressure of not having an answer and not wanting to pause for a whole minute to exercise my memory to reconstruct the last week will make me say something like, "nothing much, you?". It's that by the second or third day of being back in my routine, I forget what it was like outside of that routine, feel so immersed in it day-to-day, so unless I remember that I did have a disruption I won't really remember anything...