I also studied COBOL, in addition to Assembler, JCL, FORTRAN languages and loved the Assembler language. At the time of my studies. mainframes were not as powerful as nowadays. When I was ready to compile my COBOL program, I used Assembler language to send out a message to everyone, that "The system is going down for a reboot, please save your work and log off". This worked just fine twice, compiled my program quickly, until the mainframe operators removed my access to schedule a JCL batch jobs.
The guy, who wrote the first electronic ticker tape for Nasdaq in CICS language was my professor. He just laughed at the operators, when they complained about my JCL batch jobs...
Yeah, that was in the 80s for me too, haven't used these languages since the mid 80s, early 90s.