I had acquired for myself, a Teletype and modem before arriving at school. This meant that I could access the timesharing system from my dorm room, rather than having to trek tot he shared terminal room on campus.
Not knowing how to maintain my Teletype, I wandered into the Computing Center at the end of my first year, and discovered that they were looking to hire a Teletype repair person. I applied for the job, stated that my qualifications were that I was in the EE program and owned a Teletype, and was promptly hired!
I spent the next three years, with a permanent login to the mainframe, no time limit and access to all the free manuals I could ever want. This turned out to be handy.
After my first week of Linear Algebra, I decided I was finished finding matrix determinants by hand, and learned APL to complete my assignments without having to multiply and divide all night.
When my Assembly Language class was invited to submit our programs on punched cards, I learned how to do remote job entry using a file of card images submitted from a timesharing terminal,
As I entered grad school, I salvaged and repaired an old DEC VT05 "glass teletype" and upped my speed from 110 baud to 300 baud.
Playing around with this stuff probably taught me at least as much as I learned in my formal classes.