"Wake me up..." joke

On a bus station, an old lady got into a bus and said to the driver,
"Sonny boy, I think I'm going to fall asleep during this long bus ride.
Can you wake me up when we get to New York?" The Driver replied, "Sure
thing." But later he forgot all about the old lady and only when he went 3
hours past New york he remembered that he had to wake her up. He felt
really sorry for the old lady so he decided to go all the way back to New
York and wake up the old lady and pretend like nothing happend. Even when
all the other passengers disagreed the driver didn't change his mind.
Finally when they got to New York. He woke up the old lady and the old
lady got up, looked inside her bag, took out a pill and ate it. Then she
said, "Thank you sonny boy! I always forget to take my medication in
time!" and went back to sleep again.