Confidence!
Having confidence means you believe in yourself, you trust your own judgment and resourcefulness. In this site we define self-esteem as the sum of self-confidence and self-respect. For me, self-confidence is knowing that you have the wherewithal to function reasonably well in the world.
You feel competent to make choices, competent to satisfy your needs, to chart the course for your life. Having confidence in specific situations, such as in gaining influence with someone, would flow from a general self-confidence about your ability to meet life’s challenges and take them far.
A confident person is comfortable giving, and receiving, compliments. He’s also able to handle criticism if it comes his way because he basically likes himself and knows that a single negative incident won’t change what he thinks of himself.
Confidence is indispensable if you want to engage someone’s attention. Confidence is a fundamental trait for flexibility. It’s hard to be flexible when you’re fearful, or easily intimidated.