(Verb) To ely or pull an ely is to dismiss the preferences/input of all those around you and insist on getting your way without realizing that you might be acting selfishly. Acting egotistically in itself does not classify as "an ely" since the word is primarily meant to describe a way of life that puts the self first under all circumstances rather than at particular instances.
To pull an ely scenario
Friend 1: Thanks for inviting us to your party.
Friend 2: No problem. Sorry it is going to interfere with our weekly frisbee game but I am going to have to set up before the party before everyone gets there.
Friend 3: Wait... you have to set up... but we can still play.
Friend 1: Wow, he just pulled an ely.