Dictionary.com defines arrogance as an offensive display of superiority or self-importance; overbearing pride. 

Why?  We usually notice when other people are being arrogant or behave as though they are better than us.  But we're typically quick to look past our own overbearing pride.  

With the rise in social media and the easy access to all kinds of information, everyone has become an "expert" of sorts, displaying their knowledge for us as if they know everything and we know nothing. The morning newscast promises "information you need to know," while the evening news dispenses the "critical information" you may have missed!  It's easy to get caught in the trap of thinking that we are superior to others and not even realize it.  How often, in general conversation, do we instruct someone by saying "you need to" or "you should" do this or that?  The truth is, we are all equal, but we are only willing to acknowledge it when we think we can win an argument in our favor. 

What to expect?  When we truly fast from arrogance, our language changes and so do our interests.  We're more interested in being kind than being right.  We desire to be more filled spiritually than with the things of this world.  We are no longer interested in pleasing people, but in pleasing the Lord. Our burdens become lighter because we realize that we don't have to know everything; that's God's job.  We just have to be humble enough to be taught.