I wrote this big monster thing to help our DBAs manage IBM IMS databases under DBRC control. It had a lot of cool functions but the fun one was when our system was hard down and the IBM software engineer in charge of DBRC was helping us. He wanted us to zap a bit in a recovery control file and was about to tell us how to set up the zap but we told our datacenter dude to just use the interactive thingie.

We had to explain to the IBM guru that I'd written a thing that let people with the right RACF authority change control bits in the recons, and it knew all about the COPY1, COPY2, SPARE/DISCARD stuff. The IBM guy laughed and told us we were crazy and after we got the system back up he stayed on the line and had us tell him about the other stuff I'd written.

Plus when the big Y2K push came, the guy who'd inherited my code called up, all happy about the fact that it would keep running fine till 2072 but was also set up so that if IBM instituted 4-digit years (which they did), all he had to do was change a record description and remove and IF statement.