I took a weekend course in Excel once. Once I got back to work, I created a bunch of macros and lookup tables, and decreased everyone's workload by about half... So half the workforce - including me (last in, first out) - was let go because there simply wasn't any work to do after two weeks on my spreadsheets that I had created.
Two months later my work called me back, because something had happened with my data tables, and they didn't know how to fix it, and could I please come back?
...No. I created the spreadsheets and increased productivity. They knew that I had done it. They should have fired everyone except me, because I was the only one who was actually doing the work. Besides, I had a new job by then - which they provided me a reference for - and why would I come back just so they can fire me again after I fix all their tables?