Rabbi Yehuda HaNasi said to Rabbi Shimon ben Halafta: For what reason did we not greet you during the Festival the way that my fathers greeted your fathers? This was a polite way of asking Rabbi Shimon ben Ḥalafta why he had not come to visit Rabbi Yehuda HaNasi. He said to him: Because I have grown old, and the rocks on the road have become tall, and destinations that are near have become far away, and my two feet have been made into three with the addition of a cane, and that which brings peace to the house, namely, the sexual drive which motivates a couple to make peace, is no more.
The Gemara describes examples of the weakness and illness that accompany old age. The protrusion of the hip bone is particularly noticeable when an elderly person suffers from weight loss as a result of the weakness of old age, known as senile marasmus.
The metaphors used by Rabbi Shimon ben Ḥalafta have been interpreted in a variety of different ways. According to the midrash in Vayikra Rabba“destinations that are near have become far away” means that the ears that could once hear well, can now only hear with difficulty and from close by. The Anaf Yosef interprets “that which brings peace to the house” as a phrase that is referring to digestion, which makes peace within one’s body. If one cannot properly digest his food, he suffers significant discomfort and a lack of internal peace.
Regarding how aging affects one’s cognitive abilities, the Gemara distinguishes between people who are constantly active in their thinking and those who are not:
It was taught in a that Rabbi Yishmael, son of Rabbi Yosei, says: As Torah scholars grow older, wisdom is increased in them, as it is stated: “With aged men is wisdom; and length of days brings understanding” (Iyyov 12:12). And as ignoramuses grow older, foolishness is increased in them, as it is stated: “He removes the speech of men of trust and takes away the understanding of the aged” (Iyyov 12:20).