Dabbling on a Commodore 64 in the 80s led to a 30-year career writing and developing training for computing and programming. The first non-Basic language I learned was Shava Nerad's DECAuthor, an internal programming language designed for multimedia programming (probably the first) . We used it to program the IVIS, a touch-screen autotutor/epos unit that combined a Pro-350 (PDP-11, deskside) with a 12" videodisk player via a genlock. I cannot remember one line of code.
From then, it was VMS, Tru64 UNIX, HP-UX, and Linux, running on everything from a DEC Rainbow through an XC-series Itanium supercompute cluster, to EqualLogic iSCSI sans.
Nice to hear that folk actually read, and sometimes even appreciate, the manuals.