I said that when I was a kid, we didn't even *have* kumquats, and we owe a lot to the yuppies in terms of food.
She suggested that when I was a kid, people couldn't afford to get as much exotic stuff. I said that oranges and bananas were standard--we just weren't as interested in having a wide variety of food. (I'll grant that transport may have been relatively somewhat more expensive, and it's likely that maintaining complex inventories was a lot more expensive.) This didn't seem to register--she kept giving me variations of her theory. I don't think she was disbelieving me because I was older than she is (she seemed to be about thirty)--the impression was more that she just didn't have the mental flexibility to get that people were a little different 40-odd years ago.
Incidentally, I didn't check the kumquats at the time, but they were from Florida. The pathetic impoverished past of 1963 could have managed them in Delaware, really it could have.
We could have afforded nose rings, too (she had a nose ring), we just didn't want them.
I don't use a cane, so I can't hit her with it. However, if I see her again, I will point out that she's going to be on the other side of this conversation much sooner than she expects.
This is a "weird thing happened and I'm peeved" story, not a "people are so stupid" story. I've been stupid that way myself. I remember just not getting it multiple times when I was told that in classical China, they didn't believe in progress, just cycles, and the best you could hope for was to damp the swings down.
Free association: If you'd like a pretty good novel about actual immigrants from the past in a moderately future Philadelphia, check out Rebecca Ore's _Time's Child_.