An entitlement mentality is a state of mind in which an individual comes to believe that privileges are instead rights, and that they are to be expected as a matter of course (Adopted from Conservapedia).
An entitlement mindset can be seen in attitudes such as: A lack of appreciation of sacrifices for others, a lack of personal responsibility, an inability to accept that actions carry consequences, and this goes on an on.
The difficult reality is that we all have some areas of our life where an entitlement mindset has been established. You are limiting your potential when you view the world through this lens. Any time you catch yourself feeling or thinking anything that starts off with: "I deserve..." you are feeling entitled. Don't go and justify why you feel you deserve _______. Be awake to the fact you feel this way and do the work necessary to not be entitled. The more powerful way of being, or in other words the better way of living is to not concede your life to the decisions of others. For example, if you feel you deserve a raise and you don't get one then you may feel resentment towards your boss and coworkers. How does this help? A better way is to recognize you don't deserve any thing and instead create the circumstances on your own to get that raise, that promotion, that faster car or bigger house, etc. The world is your oyster. Go create your pearl.