If you haven't found it yet, keep looking, and don't settle.
I don’t particularly like replicating what’s elsewhere on the net, but this quote has been with me the whole day, and, you know, I’m the maximizer, so here it is again:
You’ve got to find what you love, and that is as true for work as it is for your lovers. Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work, and the only way to do great work is to love what you do. If you haven’t found it yet, keep looking, and don’t settle. As with all matters of the 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. Don’t settle.