She offers him a handful of peanuts, which he gratefully munches up.
After about 15 minutes, she taps him on his shoulder again and she hands him another handful of peanuts.
She repeats this gesture about five more times.
When she is about to hand him another batch again he asks the little old lady, “Why don’t you eat the peanuts yourself?”.
“We can’t chew them because we’ve no teeth”, she replied.
The puzzled driver asks, “Why do you buy them then?”
The old lady replied, “We just love the chocolate around them.”