And your point is . . . ?
Mercury, as a planet, doesn't change physically.
Mercury doesn't change its actual direction or its orbital speed to any degree.
Mercury doesn't change it distance from the Sun or its range of distance from other planets.
So, what really changes. Only the visual, measurable by arc, relationship between itself, the Sun and Earth. Even in this context, Mercury at five degrees ahead of the Sun, or five degrees behind the Sun, can be either direct or retrograde in motion as we see it. At these points, for example, what makes Mercury different in its relationship to the Sun and the Earth?
We can draw a parallel between the Sun and Earth as seen at the Equinox points of the year. Mercury, at these example points, is either moving towards the Sun or away from it, while being ahead of or behind the Sun. It's a "cyclic" relationship that we are looking at.
Trying to understand Mercury in terms of being direct or retrograde is overly limiting. We need to see Mercury in terms of its "cycle" or process of change.
** Ahead of the Sun, increasing relative distance, direct motion.
** Ahead of the Sun, decreasing relative distance, direct motion.
** Ahead of the Sun, decreasing relative distance, appearing stationary.
** Ahead of the Sun, retrograding and decreasing in relative distance.
** Conjunct the Sun, retrograding.
** Behind the Sun, retrograding, increasing relative distance.
** Behind the Sun, increasing relative distance, appearing stationary.
** Behind the Sun, decreasing relative distance, direct motion.
** Conjunct the Sun, direct motion.
** Ahead of the Sun, increasing relative distance -- at the first step above.
As I have indicated in other threads, each of these has subtle meanings relative to the other "phases" of the cycle. Each of us needs to meditate on these changes in the Sun-Earth-Mercury relationship in order to actually understand what we are seeing in our charts. Dave