(Strip Number 659, Original Publication Date, 19 July 1984)
Panel 1: As Mike plays Space Invaders, Vicky the flight attendant comes over to tell him that the plane they were meant to take has been grounded and they are waiting for another one.
Panel 2: The two of them agree that the replacement plane is taking a long time to get ready.
Panel 3: Michael thought-bubbles that this must be what they mean by "jet-lag".
Summary: Jet lag is actually something else but Mike won't find out what it is until he experiences it later on in life. That being said, this is a pretty good guess based on what little he has to go on. The problem is that Lynn doesn't see it that way. The real punch line is that a childish misunderstanding is his way of making Elly's life worse by being ignorant.