I left University of Alberta in 1989 after completing about two years of my degree to co-found a startup with the thought that if it failed I would go back to get a degree at a better program. The startup was a success and I have never gone back to school.
Sadly, in 1988 the University of Alberta CS program was stuck in a 1970s data processing curriculum and, for undergrads, had neither PCs or Unix. I had already been making money writing applications software for PC for several years and there was no way I was going to go work for an oil company or provincial government doing mainframes.
I did miss out on some things by not completing. I had very much wanted to take the compilers course offered by Jonathan Schaeffer (of Chinook checkers and poker bot fame). Had the U of A program included internships or co-op, more unix or PCs and a more modern curriculum I probably would have stayed. Indeed they closed the program to new students for a year in the fall of 1989 to retool it and modernize. The revised program was much better (In irony, I was hiring interns from the program about the same time as I would have originally graduated).
It is still strange when I have to explain sometimes that I have no degree. I can't imagine getting a CS degree just for the piece of paper. I can understand why someone might need that paper in addition to the skills, such as for a TN work visa. Thankfully I have not. If I did go back, and in my 50s I would feel like I was stealing a seat from someone who really needed it for their career, I would go for math, statistics instead of CS, a degree complementary to the CS skills already have.