When I was six or seven (early 70's) I was walking to the grocery store with my mother. I climbed up on the fence at an old loading dock and looked down in the pit. There was a knife laying down at the bottom. I was all excited. I showed my Mom and asked her if I could have it. She said I could if it was a pocket knife, she probably felt that was a safe answer because the blade was out and it looked like a nice fixed blade kitchen knife. When I climbed down there IT WAS A FOLDER!!!! I danced about at my good fortune and how lucky I was.
I don't remember the maker, but it was a slipjoint that had some kind of black phenolic handle and no liners. It was about 3 1/2" to 4" long (closed) with a fairly thin boning type blade (straight point, not clip or drop point) I carried it around for a week and had to keep it in my pocket. Then we went to visit my grandfather. He made knives and also collected them. He sharpened it up and tested the edge (tool steel, not stainless) and proclaimed the steel to be very good. Hot dog, what a lucky kid! My grandfather had not told me it was a piece of junk.
A week later the knife "mysteriously" disappeared. I looked everywhere to no avail. I was crushed.
A few years ago my grandfather died. In his collection of hundreds of knives I found one that looks exactly like the knife I remember. Nobody even remembers me finding the knife now, but I think my parents decided that perhaps I was a bit young for the knife and (without my knowledge of course) gave it to my grandfather for safe keeping. It's a Case.
Other than that, I've never found anything worth keeping. A few Chinese knock offs that go out the window to the first homeless panhandler guy I see (which, here in Austin is every freaking corner).
On the other side of the equation, there's been some lucky sons-of-bitches that have found a few great blades that I've lost. A Gerber bowie that I left on the back bumper of my truck, a couple of SAK hikers, some Gerber folder at the bottom of Lake Travis, and, just a couple of weeks ago, a Benchmade Ritter Grip (damn! I'm still pissed about that one).