this happens to me sometimes as well. it used to happen more often a few years ago and seems to happen less often these days. it used to be almost every time i had red wine, but now it is few and far between. thanks all for all the knowledge.
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 .