Hesitation is a word that ruins many and separates the few. I think it is defined by your experiences and what you do. I was hesitant the first time I went to observe a teacher, because I had never done it before. I was hesitant the first time I had to deal with an angry parent, because I understood the mood. I was hesitant the first time I had to speak in front of a large number of students. I was hesitant the first time I had to speak to my staff.
Hesitation always gets a bit easier to deal with. It always leaves you a little queezy in your stomach. It always makes you think twice and refine your practice. It always is there, it is your conscious, that has your back.
It is your filter, your second guesser, your corner man. It is your feelings, your brakes, your heavy hand. When you answer its questions, when you make it feel okay. You realize eventually it is a gatekeeper, not the ruler of the day. You fight it and love it, hate it and thank it, you need it and want it to leave. For hesitation is the voice in your head that eventually allows you to be free.