Undoubtedly, Ryan Holiday's Ego is the Enemy is one of the books that left the deepest mark on my memory and that I noted the most quotes from. If you currently see yourself as a highly successful person surrounded by dozens of enemies, my immediate advice to you is to get your hands on this book and devour it as soon as possible.
So, what is 'ego'?
If you go through the dictionary, you will come across a definition like "a sense of self-importance and self-esteem". I would prefer to define it like this:
Ego is a subconscious wall you set up between you and other people to ward off your fears: On this side, it whispers how awesome you are and on the other side, it judges people away from you.
That is to say, the ego's food is fear, its armor -false- confidence, and its weapon is judgment.
The problem is that a person driven by their ego is almost certainly not aware of it. For him, criticism is an assault, and praise is an endorsement that is never enough. The person is so trapped inside his own mind, and he believes in the image he has created so much that he is incapable of analyzing what is going on around him or the feelings and thoughts of the people in his social circle. Here is where the biggest problem arises:
No one actually cares
There is a famous saying:
People don't care how much you know until they know how much you care.
Of course, there is also this:
Your freedom begins the day you realize no one is thinking of you.
Regardless of your profession, looking down on people and isolating yourself from your environment never ends happily. You may indeed be doing a far superior job than theirs; maybe you really are more handsome, smart and educated than them. But you can't force anyone to prove or accept any of this.
Don't put stones in your own path
This kind of display of superiority, the urge to defend yourself at the most innocent criticism, or the habit of judging what you disapprove, can temporarily protect your feelings or satisfy your ego. But in the long run, all it will do is turn you into an unloved, lonely person. Just because you think highly of yourself doesn't mean that others will do too, and the people you judge will probably never change; accept it.
Whereas, in life, you can go a lot farther by making the same effort. All you have to do is get out of your mind, be present and pay attention to your environment. Genuinely listen; discover the hidden fears, worries and desires behind people's words. Remember names, note down birthdays. And most importantly, tolerate even the most cruel criticism, and treat even the smallest person with respect.