Perhaps . . .
Perhaps it might be helpful to start your considerations about "retrograde" meanings in astrology based on the following:
** For the most part, planets tend to move forward through the zodiac signs.
** Before turning retrograde in motion, the planet slows down and seems to briefly halt. We call this a "station."
** After making a station (or reaching a stopping point) the planet appears to move backward within the zodiac. This is its retrograde phase.
** The retrograding planet will, at some point, slow in its retrograde motion and then briefly stop. This is another station point.
** The planet will resume forward motion, gathering speed.
** At one point, while going forward, it will pass over the point where it had last stopped and turned "retrograde". It will continue past this point as it moves ahead until its next retrograde point.
Now, there is a lot more to retrograde cycles and interpretive considerations then just the few points made above. But, starting with these points, one can start to gain an understanding on how to deal with retrogrades.
When a planet reaches its first station point we can see that place and time as a pause point where something important needs to be considered.
As the planet, Mercury in this case, slides backward it is re-covering space (and experiences) that has already been covered. What might we learn from again "reviewing" this period? Do we need to re-do something? Perhaps not, we might just need to think about what has recently passed through our life.
At the next station (where retrogradation ends) we reach another pause point. What might we learn here, now? What planets now aspect this point? What planets aspected this point when we turned retrograde at the other station point?
We now find the planet, Mercury, moving faster and faster forward, still covering ground/space that the Sun has already traversed. Does this mean that we are learning from the "world" and what it has done in the past many days without our direct guidance?
Mercury continues forward, passing its turning-retrograde station point and still trying to catch up with the Sun. As it hurries past the first station point what will it remember, what problems will it have solved or resolved to address. Mercury conjoins the Sun and is re-infused with energy and inspiration. As it rushes ahead of the Sun, it eagerly gathers its own experience in its temporary leadership role. How will it act now?
This simple series of views and questions will lead one into a better understanding of just what a retrograde mercury might mean, in my opinion. Dave