I never dreamed MATLAB would become what it is now. It began almost 40 years ago as a simple calculator my students could use for matrix operations. Today, extended by dozens of specialized toolboxes and Simulink (a block diagram environment for simulation and model-based design), MATLAB has evolved into a mature programming language supporting a rich technical computing environment. Its use has spread in sometimes surprising ways far beyond the original context of academia to a wide variety of applications in industry and business. So MATLAB has come a long way from being just a "matrix laboratory."
As chief mathematician for MathWorks, I love to see the mathematics that underlies all these applications and ties everything together. The mathematics may be invisible to the user, since one of the objectives of some tools is to hide the math, but it can be found by poking deeply enough.