Our son had only heard his grandfather pray at Thanksgiving, Easter, and other special occasions; when he, typically, said a long prayer over the food. One night, after a fun camp-out and fishing trip, grandfather (to our son's surprise) asked a very brief blessing on the food.
With a gleam in his eye, our son grinned at his Grandfather and said, "You don't pray so long when you're hungry, do you Grandpa?"