People don't choose their calling, it chooses them.
Purpose is the quality we choose to shape our lives around.
Information does not change behavior. Practices do.
The original Greek word for enthusiasm meant "to be filled with God." When we are "filled with God" we tend to lead on purpose.
One of the reasons people get old - lose their aliveness - is that they get weighed down by all of their stuff.
Our world is incomplete until each one of us discovers what moves us - our passion. No other person can hear our calling. We must listen and act on it for ourselves.