I have had characters walk around with powerful items they never identified and thus never used to their full extent. That is kind of like missing a hoard.
I've done this as a PC. But, in my defense:
The opening scene of the campaign for my character was breaking out of the brig of a ship I had been kidnapped on. I, (a 3rd-level fighter), overpowered the one guard, (a 1st-level fighter), and took his sword and pocket change.
I joined with the other PCs and we got off the ship and started making our way to a town. In the three game sessions, one of the other Players kept making a big show of examining every little item we came across or looted. She even closely examined a frickin' rock in the middle of the road. Just a character quirk, I figured. Weird, but not a problem.
When we made it to town, we went about selling our loot. I wanted to sell the broadsword and buy a two-handed sword. I looked in the Player's Handbook, saw 10gp was the buying price. "Can I sell it for 5gp?" I asked the DM.
"3gp," he answered.
So I erased the sword and added 3gp to my sheet.
At the next game session, the other Players were laughing at my loss.
That sword I sold -- that I had originally taken from a no-name sailor guarding a ship's brig -- was a powerful magic weapon. Had I examined it, I would have found the runes to activate it. The DM had told the other Players a couple of sessions before I sold it what it was, and he was wondering if I was going to look it over at some point. That's why the other Player was having her character closely examine everything we found, trying to hint to me to examine the sword. (The sword wasn't the only piece of looted/stolen/captured equipment and treasure I had one me.)
And to top off the stupidity, the DM laughed that not only had I sold it as a normal sword, he even haggled me down on the price.
Oh come on!
First: I got the sword off a basic guard. Who thinks the sword they got off the pissant ordered to watch the prisoner might have an artifact?
Second: I had the sword for several game days, and the DM assumes I never looked at it? I mean, isn't it assumed PCs do basic care on their equipment?
Third: I didn't get haggled down. I asked the DM what I could get for it. He told me.
That situation was not right.
Bullgrit