That's impressive! I had to learn Fortran as my "language" in undergraduate college (mid-70s), back when it was computer cards, and a large program was a few hundred cards :) I mostly forgot it but had to learn again a few years later when in graduate school (the first time). I was testing the use of a contracted computer service via a 56K Baud modem, by writing a program to calculate pi to something like 8 places. It took a few seconds of the computer time, and got billed at a couple hundred dollars, if I remember correctly :) I would later go back to grad school and had to learn Fortran for a third time, this time writing significantly longer programs :) I ended up writing one to do image analysis, and if I saw a printout of that program today, I wouldn't even know what it was doing (I remember that I had to do bit manipulation of the binary image files; totally amazes me today to think that I actually wrote that program!)