Until the time of Avrohom,
there was no such thing as wrinkle cream.
That's because no one's body ever aged. Men remained tall, dark and
handsome until the day they died. This presented serious problems and
unique challenges (especially to the Senior Citizen Centers that were
filling up with 15 year olds who liked to play bingo!).
Avrohom Avinu was particularly concerned with two issues: Tshuva (repentance) and honoring the elders.
If a person lived his whole life without feeling the pains of aging, he
might push off doing tshuva before his death. The aches, pains and
aging process serve to remind us that this world is only a temporary
stop-off and that one must do tshuva everyday.
And honoring elders; Can you imagine 80 year olds holding doors open for
17 year olds? 90-year-olds giving up seats on the bus for
three-year-olds? Rebbes standing up when students walk into the room? I
tell you - honoring elders in those days was a coin toss!
So Avrohom asked Hashem to age people's bodies as they grew older so
that people could tell each other apart. Hashem agreed and made Avrohom
the first one to be "blessed" with physical aging.