Many times I'll reply to a pm and I'll get a "new PM" flag. When I go to look, all that's new is the PM I just sent. The last thing I want to happen is that I find out I'm pm'ing myself
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 .