My Deepest Joy

Fredrick Buechner says that vocation is the "place where my deep joy meets the world great need." The world's needs are many and great. I am aware of them. But what of my deep joy? Can I name it? And how is it related to any or all of the world's needs. What sounded simple at first leads me to a great exploration. What do you think about this quote and where are you in the pursuit?