Why do we Eat?

One of the chassidim of Rav Aharon HaGadol of Karlin zt”l was with him when the Rebbe’s assistant brought him an apple. The Rebbe took it, made a blessing, and ate it. This prompted the chassid to think, “You know, I guess the Rebbe can also get a craving for an apple, just like me.”
At that moment, Rav Aharon turned to his chassid and said, “I was just thinking: what is the essential difference between you and me? I eat apples, and so do you. I make a blessing, and so do you! The difference is that when I get up in the morning, I contemplate the apple tree outside my window until I am filled with wonder and gratitude toward Hashem. I delve deeper, I recall the true meaning of what an apple is, and I become filled with a powerful yearning to make a blessing…but since I can’t without eating, I ask my assistant to bring me an apple.”
Rav Aharon continued. “You, on the other hand, see an apple tree and think how good its fruits look. You suddenly feel a burning desire to eat an apple, but since you’re good enough not to steal one, you spend a little money and buy one from the grocer. After you get home, you are all set to eat the fruit, but your fear of heaven stops you short. You worry that maybe you’ll lose your teeth as a punishment for failing to make a blessing! So you stop just long enough to make one before you eat.”
“You see,” he concluded, “I eat an apple just so I can make the blessing, and you make a blessing just so you can eat your apple!”