The first word of any answer given by a know-it-all douchebag, said to give the effect that they were already speaking when you asked your question or requested their opinion, in order to feign superiority or to imply that they knew what you wanted to know before you inquired.
Man: "What sort of food does that restaurant serve?"
Know-It-All Douche: "So, they have asian fusion and cali fresh, not that you would know what those things aaaaaaaaaaaarrrrrrrre..."
Man: "Is that new game any good?"
Know-It-All Douche: "So, this game was developed on the new platform, not that you could understaaaaaaaaaaaaand it..."
Often and repeatedly--sometimes incessantly--used by speakers incapable of beginning an idea at its beginning, those seeking to stall for time until a thought congeals, or those desiring a familiar starting point as they venture into the dangerous world of communication.
Beginning each sentence with "so" has been called "using a verbal tee" to enhance one's chances of hitting an idea squarely.