College forced me to learn a lot of stuff I wouldn't have bothered to learn before. Stuff I had no idea would become useful and if I ever needed it may not have had an idea to look for it.
I have an interest in programming languages and interpreters--college helped me find and cultivate this interest. I'm working on a startup doing a lot of natural language stuff--college gave me the foundation necessary to teach myself the tools of this field quickly.
The theoretical underpinnings of stuff don't go away. Understanding different string matching algorithms can apply to writing an efficient style checker, not just making an asinine version of strcmp.
Granted this is all oriented towards technical stuff. I suppose if I wanted to be just an entrepreneur I could save money and buy a Subway franchise. I don't think a college education is necessary there either (but I'm sure it doesn't hurt).