The demands of Leadership
Leadership is about pushing others so that they give the best they have, sometimes things that they didn't thought they were able to do. To get the best out of others, however, you have to get them out of their comfort zone. More important, if you want to do great work, you have to force yourself, or put yourself in a position where you are forced to do things you thought impossible.
The problem is that if you don't have the habit of pushing yourself like this, you won't be able to help others do the same. These are the demands of leadership.
This is easier said than done. It's not just about putting extra effort, but choosing wisely what are you investing your effort in. It means overcoming your fears. (Fear of failure in front of your boss, your peers or reports, for instance.) And since nobody has infinite time, it also means choosing what you are not going to put effort on.
A great way of stepping out of your comfort zone is taking responsibility for things that are not strictly under your scope. Or assuming hard challenges that no one is assuming. Take initiative instead of complaining. Most challenging, however, is doing things in which your primary motivation is not the attractiveness of learning something new, or working with talented people, but helping others give the best as persons and professionals. Activities in which your 'return' on your actions are not immediately evident.
The thing is that if you never do things like this, you will hardly understand that there are people whose motivation is the why and not the what. There are motivations that out-weight status, the attractiveness of learning, a great place to work or a promising career. Understanding this is indispensable to be a leader.