Have you tried it? I had to go about 2 weeks without internet when I moved apartment. The only access I had was the local café and I only used that to send files for work (so I went in spent 20-30 minutes on email/dropbox and then left). It's amazing how difficult it was and how much it changed how I lived for those two weeks.

There were positives (I read more, went out more etc.) but they didn't last too long. The time my roommate and I would have wasted on the internet previously was now allocated to TV. Rather than only watch shows we liked we channel surfed for hours. It was kind of like being thrown back in time to how I wasted time when I was younger.