Robert Lawson Brown, Mathematica user since 1989
I wish I could remember precisely when I purchased my first version of Mathematica. It was very early on, at the MacWorld Expo in San Francisco of either 1989 or 1990 or 1991. I purchased my copy right out of the exhibit booth, from a heavily bearded and highly enthusiastic individual.
My first professional use of the program was for analyzing the precision of a stepper motor driven mechanical stage, used in high end semiconductor processing equipment. I had been using a statistics dedicated program, but wanted to have a better graphic generating and report generating system. The workflow was that I would receive stage measurements in the afternoon. I would key these into a file on a Mac, and generate a fully formatted report with Mathematica. Early the next morning, when the manufacturing engineers met for their start-of-day review, I would present the report. Then I would wait for the next set of data to come in.
In later years, I used Mathematica both professionally and recreationally, and kept up the latest versions. When the Premier Subscription service was offered, I started with that and have been an annual subscriber ever since. Recently, I used Mathematica to generate a set of multi-hued Apollonian circle graphs, for a friend who needs such for illustrations.