I did 21 one semester, but 3 of those hours were pretty much for free. I essentially got 3 hours for an internship so all I had to do was go to work every day and fill out a book about the stuff I was working on and meet with the department head once a month.
Outside of that semester, 19 was the most I took of legit classes. Coincidentally, it was my first semester in college ever so I had no idea what I was getting myself into when I scheduled. I also worked ~30 hours a week that semester so I averaged about 2 hours of sleep a night. 5 of the worst months of my life, easily.
This post was edited on 3/20 at 9:43 am