Marshall McLuhan coined the phrase "The medium is the message" - and I'm sending you this message to reveal its meaning by illustrating his point with a literary example from an author whose...
Depending on the context, it could mean a quick stop somewhere, meaning "I'm going in, then coming right back out... in and out."
It could mean that there is a back and fourth motion occurring...
It means exactly what it looks like it means - it is a question. "Did I remember?" To remember means to call something up in your mind, from your memory.