Elderly is relative, I think

What is elderly?  I've been looking on the internet and quizzing my customers about this.  I referred to the gentleman who mistakenly got in my car last week thinking it was his as elderly.  That is as differentiated from me who is 70.  Hmmm.

One of the youngsters calling me from the Metropolitan Opera (why do causes you donate to then constantly harass you for more money?), upon discovering I was in Florida and that I attended the Met in HD at my local movie theater couldn't resist asking me about the average age of attending viewers.  I responded that they averaged about 78-82, I thought (though this is definitely not scientific).  He didn't inquire about ethnicity, but that is easy--there is a black couple (she is an opera singer).  That's it for ethnicity.  Anyway, about age.  The young man was disappointed.  He wanted to hear that there was a great resurgence among young opera lovers.  I responded that he shouldn't be disappointed, since the viewers here reflected a large segment of our community.  You must understand that we do have young people and public schools, but their parents too often are the service personnel dealing with this affluent community.  They are the landscapers, lawyers, bankers, hairdressers, retail shop owners (like me), etc. etc. etc.

Today was a Mozart opera and I spotted several 40-year-olds and some 50s, so word is spreading among the younger generation.   And it had wonderful melodies, almost making up for the Tempest. 

But I digress--what is elderly?  I know Florence who at 93 runs 5k races.  She may not whip a 40 year old, but she'll beat me!  Is she elderly?  Middle-aged used to presume 45 or 50.  I think now it has edged older and middle-aged is 65 or 70.  What do you think?