Computer programmers have a conversational habit which, so far as I know, is peculiar to themselves. Ask a question of a computer person and surprisingly often he prefaces his response with the word "so." ("Why did you decide to quit your old job for this two bit startup?" "So, I thought the technology was really, really cool.") The unexpected "so" is one of those fragments of life that you block and store in memory in spite of its probable insignificance, as you do when you hear an adolescent girl punctuate her clauses with the word "like."
The obvious explanation for "so" is that the speakers, by adding a nonce word, buy themselves time to consider their responses. The trouble with this explanation is the rush of words that typically follow "so." The computer programmer does not say "So.....I thought" but "SoIthought." Another possibility is that the word "so" reflects computer logic or language. It would hardly be surprising if computer language has in some way bled into the spoken language of the computer nerd. But the several expert programmers to whom I have put this theory find it risible: There is no equivalent to "so" in any computer language or logic they know.
Yet a third explanation is that "so" reflects a simple desire to impose the semblance of logic on an essentially illogical event, human conversation. After (or, rather, before) all, "so" implies that the answer follows directly from the question.
But the more you delve into "so" the deeper its mystery. For example, it cuts across all borders within the computing class; I've heard it from Americans, Chinese, Russians, Indians and Europeans of all stripes (red and white stripes, blue and green stripes, etc.). How could it be that people for whom English is a second or even third language emerge with the same strange verbal tic as native speakers? And why are these otherwise acutely conscious human beings so unselfconscious about this single strange tic? While teenage girls are obviously aware when they say "like" computer people are oblivious when they say "so." In a recent interview three computer programmers bandied four consecutive questions with their introductory particles. I stopped the conversation and asked them why "so"? They had no idea. Do you?