The astronomy first
Retrograde motion is real and entirely understood. A planet does not actually reverse direction; it appears to move backward against the fixed stars for a period because of the relative motion of the Earth and that planet along their orbits. When the faster Earth overtakes a slower outer planet, or when the geometry of an inner planet's orbit produces the same effect, the planet seems to loop backward before resuming forward motion. Mercury, being close to the Sun and fast-moving, produces this apparent reversal several times a year. None of this is in dispute, and the classical Indian astronomers calculated it with precision.
What the tradition does with it
Vedic astrology recognises retrograde motion — vakri, 'crooked' or 'turning back' — and treats it as a genuine modifier of how a graha expresses itself. A retrograde planet is often read as more internalised, its energy turned inward or its themes revisited rather than advanced cleanly. Interestingly, the classical view of retrograde strength is not uniformly negative; in some schools a retrograde planet is considered to gain a particular intensity. The tradition treats vakra as a nuance to be weighed against everything else in the chart, not as a standalone forecast for everyone alive at once.
Where the popular version breaks
The familiar internet claim — that Mercury retrograde universally breaks technology, derails travel, and scrambles communication for everyone — has no basis in the classical literature and does not survive scrutiny. A genuine astrological reading is chart-specific: a transit means something only in relation to an individual's own placements and running periods. A blanket prediction that applies identically to eight billion people is, almost by definition, not astrology but a meme. The fault is not in the concept of retrograde motion but in stripping it of the individual context that gives it any meaning.
A reasonable stance
The reasonable position is neither to mock the idea nor to surrender to it. Retrograde motion is real, the tradition has a measured view of it, and that view is individual rather than universal. If a Mercury retrograde coincides with a meaningful pattern in your own chart, it may be a season worth reviewing decisions and double-checking details — sensible advice in any season. What it is not is a cosmic excuse handed out equally to everyone. Treat it as the tradition does: a modifier to be read in context, and never a sentence passed on the whole world at once.