Remember how you spoke/heard, communicated/listened, interfaced with others and how it made you feel on Wednesday / Thursday (November 15/16) of this past week?
That was 13 Sagittarius, the degree of the Zodiac where the upcoming Mercury Retrograde stops before it turns around again and stations Direct.
Even though Mercury Retrograde does not begin until December 3rd, we're in the pre-Retrograde period because we'll be revisiting 29-13 Sagittarius and back again between now and January 4th.
December 3rd also happens to be the Full Moon, with the Sun at 13 Sagittarius (the degree of the Mercury Retrograde) and the Moon opposite at 13 Gemini.
Which House of your Natal Chart contains 13-29 Sagittarius? That's where all the lights/camera/action/stop the cameras, rewrite the script/take two action takes place. Conversely - an "opposing effect" may occur in whichever House 13 Gemini falls, as that powerful Full Moon in Gemini which kicks off the Retrograde is, of course, associated with Mercury (the Ruler of Gemini) and therefore comes under the category of "A Mercury Retrograde in Big-Picture, Don't Bog Me Down With The Fine Points Sagittarius with a Heaping Side Order of Data and Details Delivered by Gemini".
Pre-Retrograde: November 15-December 3
Retrograde: December 3 - December 22nd
Post-Retrograde Return: December 22 - January 4th