Buddhism doesn't define the ego. As far as I know, there is no word "ego" in the scriptures. Often when we think in English of the word ego, we are thinking of our personality, our representation who we think we are, our statistics, etc. Where does the ego get its energy from if we are thinking of our personality level, well, it is all in our craving, in our desires, it's in attachments to the eight worldly dhammas, "I want to be famous, I want this, I want that". Rosemary and I are very happy that when we started teaching we didn't want to start teaching. We didn't want to teach at all, we were asked, we were kind of pushed into it. But we know other people who want to be a teacher, who want to be something in order to achieve status, fame and whatever else, and that can be very dangerous. That's coming from what we call in English an ego-base, the wanting of praise, the wanting of fame, the wanting of gain, and the wanting of pleasure. So be careful as far as wanting, wanting, wanting because that's where the ego is really coming from, it is our craving and it's based on the eight worldly dhammas.