I'm 19 - business/design (basically creating shit) is more important to me than uni. I've been too 3/4 lectures and no classes this term, and i don't regret it.

Just do it, you shouldn't even have to think about it, and find somebody just as ambitious, doing it on your own gets lonely.

Phase into it, even when im in a lecture im sketching something, you'll find out whats really important (your degree or creating your own company) to you as soon as you start.