I think it means that success has to be worked for and always is being worked on. People are working on being successful so it would mean that their success is under construction, I would think so.
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...