Your work is going to fill a large part of your life, and the only way to truly satisfied is to do what you believe is great work, and the only to do great work is to love what you do. If you haven't found yet, keep on looking. Don't settle. As with all matters of heart, you'll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So, keep looking until you find it. Don't settle.