Ask Amy: Hikers encounter trail of rudeness

Dear Amy: Why do people have to be so rude to old people?
I need to know how to respond when someone has been rude to me or my friends. We are three people in our seventies. We live near a national park and have been hiking for nine years. We have probably hiked more miles uphill than the people who constantly insult us.
Here is an example of the rudeness: Two of the ladies have full heads of beautiful white hair. I color mine, so I look younger.
Twice now, someone has said to me, “Are you