If you research the phrase "old chestnut" you will see that there is a literary explanation that an "old chestnut" is a tale that has been told so many times that it is no longer funny or interesting. If you research how long chestnuts stay fresh, you will find that they must be stored under very precise temperatures, and even then will not keep long. 
When I was a kid, I remember telling my father a joke that I had just heard and thought hilarious. I think it was probably a knock knock joke, since I couldn't have been more than six or seven. His response was "oh, come ON Viriginia, THAT old chestnut?!" It was a phrase I continued to hear from him on and off for the rest of my life.
Somehow, my dad thought I should have come into the world with all the experience and knowledge he possessed, and therefore I should have already developed a discernment and sophistication that could only belong to an adult.
On one level I suppose that was a vote of confidence in terms of his expectations, on another level, it pretty much squashed my enthusiasm for what I had only recently discovered for the first time. In an effort to exonerate him from any charge of being an unfeeling and mean-spirited adult, I determined that I must be more careful about how I brought things to him that, for me, were new and extraordinary experiences. I think we both missed out on a lot.
When I was an adult, and had a fairly wide experience of the world, (9 countries in Europe, a career at a University in a staff postion, and two children to my credit), I was reminded rather sharply that once again I had brought him an old chestnut. I had been listening to a record (vinyl!) that was labeld "Hits of the 17th Century," which, by virtue of its rather 70ish title, was clearly bits and pieces of some of the familiar bits of 1600 music. The Pacabel Canon in D was one of those pieces. He and my mother had come for a visit, and when that slice of the record came up, I felt that visceral ignition that a piece of music can inspire.
"Dad! Have you heard this? I absolutely LOVE it! If I were a piece of music this is what I would BE!"
I should have expected the response -- but, never daunted, I tried again. "THAT old chestnut? Really, Virginia?"
I took it personally, and felt like a very old chestnut, indeed. A bit rancid, a bit bitter, very unpalatable. After all now I WAS a fully grown adult, and I should have KNOWN BETTER.
Here's the thing. You can't know better if you've never heard/seen/experienced something before. Sure, you can learn from others' experiences -- but not EVERYTHING.
Recently one of my granddaugthers and I were at a local park where there is a duck pond. She spent about twenty minutes running back and forth to get duck food to feed them, and then another twenty with her arms folded on the top of the fence watching them. Later that day she said "Isn't it amazing how duck feathers are waterproof? I watched them dive under water again and again, and every time they came up the water was just little balls on their wings!"
Now you can tell a kid that duck feathers are waterproof, but until they observe that phenomenon for themselves, it may never mean anything or even be remembered because it really isn't yet relevant. It could be that only until a thing is observed as a miracle outside one's previous knowledge of the world, that it can truly be appreciated and given the awe and respect that engenders.
I am careful about making a judgement on anyone who shares new discoveries with me, because of my dad's too-frequent dismissal of my own discoveries as old chestnuts, or his other favorite phrase, "Come on. Everybody knows that!" So I am grateful for the awareness. And I am still practicing the skill, however hard it was won. I slip, as you do, because what is done to you may often come all-unawares out of your mouth and be passed on to the next generation.
When I went to High Tea at a local tea cottage, they served a delicious chestnut tea; so delicious that I had to have some to bring home. Now I can savor that chestnut over and over again. Favorite chestnuts need no careful preservation. You can enjoy them again and again, even if other people may want to tell you "that old thing? I moved past that, heard that, experienced that, a long time ago."
I still love the Canon in D -- and I still love my dad. Never old chestnuts to me.
