Why is your service so expensive

One day Leonardo da Vinci was approached by a lady and asked him to draw something for her. da Vinci quickly sketched something on a piece of paper and handed it to her. When she asked how much she owed him, he quoted a very high price. The lady was shocked and protested, saying that it only took him a few moments to draw it.

da Vinci then responded, "No, it took me a lifetime of practice to be able to draw this in a few moments