Knowledge without understanding is no knowledge at all.
College gives you the fundamental building blocks to understand your experiences, increase your problem solving skills and gives you the ability to see things that someone without a college education would likely miss. Naturally this is all assuming you get a degree that is applicable to your field of work.
Now if your only goal in life is to mow and blow, you probably don't need a college education. That said, if you want to set yourself apart from the rest of the field, then an appropriate college education will get you there far quicker.