In the beginner's mind there are many possibilities, in the expert's mind there are few. "Be a beginner, empty your mind of answers, and learn to live and love the questions."
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .