What is Elderly?

While on the phone with a store's Customer Service last week I heard that I was elderly and it kind of threw me for a loop.  I'd been trying to get something done about something that had been delivered and wasn't right.  They had delivered it via FedEx and their Customer Service suggested that I pack it back into its box and have FedEx pick it up at their expense.  I explained that it had come in a huge bag, not a box and that there was no way it would now fit back in the bag.  So they suggested that I take it, as is, to their nearest store.  I explained that we had small cars and that it wouldn't fit and that I was too old, I gave my age, to be manhandling it around.  At that point they were out of suggestions, I sighed and said I guessed we'd find a way to make it work.
Shortly thereafter I received another phone call from someone higher up in Customer Service who apologized, said they hadn't realized how elderly I was and that they'd have FedEx pick  it up and bring packing supplies to do it with.
After the call I sat there for a while and thought about what it means to be elderly, something I never think of myself as being.
What is elderly?  Since last week I've walked at least 2 miles a day, did a day of aerobics, renewed my driver's license, climbed a million stairs each day, helped move our old couch out of the family room, helped move our new mattress into the bedroom, hung out about 5 loads of wash on the line, cooked and cleaned every day, made candles, pillows, decorated the house for Autumn, read 3 books, and today I cleaned out the refrigerator, mowed the lawn which is almost an acre and pulled a ton of weeds.
Does a number make you elderly?  I think being elderly is a matter of health and a state of mind.
By the way, after their offer we decided to keep the thing and find a way to make it work, I didn't want any favors because I'm elderly.