I don't regret the fact that I went to college. I did a ton of growing up, met some wonderful people, and learned a great deal about writing. However, in terms of sheer learning, school is only so useful. There are examples all around you. It's impossible to go a day without seeing words. Somebody wrote those words.
I learned how much difference one word makes by looking at writing in a restaurant. I watch commercials and read posters. People are communicating constantly, now more than ever. Heck, you're reading this right now (and as of this writing, it is not in a textbook). Examples are all around you. What's good? What's bad? What is effective in educating? What is effective in persuading?
What school does offer, though, are tools. It taught me how to see the examples all around me, how to evaluate them, how to put into words what they do and how they do it, and how to go about internalizing those abilities for my own uses.
School is by no means useless. I do not want that to be the message. I simply want to remind people that once you know how to teach yourself, the material can be found everywhere.