SHE SAID IT in the car. She said it after lunch, after she had bowed her head and prayed silently with her lips moving, saying thank you to God for the soup and for the bread and for the cantaloupe also. She was in the car and was being driven back to work, and she said the whole thing reminded her of when her great-grandmother died. She was talking of something she lost on the bus. You have to understand.

She is young, 24, works on the Hill as a legislative aide and has been to Harvard and to Israel and to some other places.She plays the guitar. That's important. She is sandy-haired and innocent looking, and one day she took her guitar music, all of it, and put it into a folder so a friend could borrow some songs. She left the whole thing on the bus. She was reading Turgenev, would you believe, and she got so engrossed she left all her music on the bus.

"He's such a good writer," she said. "I started reading, and I read 35 pages."

That was two weeks ago. She called lost-and-found, and they said they had found nothing. She described what it was. It was not exactly music but her transcriptions of various songs. She would hear a song and then copy down the words and put the guitar chords over them. She showed me one she still had. It looked like scribbling, nothing that made any sense, and the one in Hebrew looked like scribbling in reverse. The lost-abd-found people were very polite. They had nothing like it.

Her name if Debbie Cooper. She's from Memphis. Every day she would call the lost-and-found, and they would tell her what they had. They had umbrellas and purses and briefcases. They had things that looked like things - things you would save if you were cleaning out a bus. They did not have a blue folder with 300 or so songs in it that was left on a seat and covered with three newspaper articles Cooper had not had time to read. She would hang up the phone, and in the beginning she would cry. After a while, she just stopped calling. The songs were her snapshots. She had a song for places she had been and people she had known and, at night when she got home, she would pick a mood and maybe a memory and pick out a song.

"I would pick a mood," she said. "I could go through and just recognize a song from the edge of the paper."

She called me eventually, tentatively, wondering if I could do something. I could not, of course. I cannot write a column every time someone loses something on a bus. The papers are full of these sorts of stories - stories, too, of cabbies returning the Hope Diamond or something after it has been left on their back seat. This has never happened to me. When I lose something, it stays lost and somewhere in this world is a collection of my wallets and maybe 100 umbrellas.

But I listened and I kept saying I could write nothing, but I wanted to. I really wanted to.There's something here that appeals to me. This is not about someone finding a wallet and taking it or lifting an umbrella when the bus pulls into the last stop on the line. This is about someone taking something that looks like junk and tossing it out - not stopping to consider what it might be.

Cooper and I talked about this. We played with the concept and finally, while we were having lunch, I thought of my old bike, the one I had found while vacationing with my parents. I was just a kid, maybe six or seven, and I found this old, discarded three-wheeler and claimed it for my own. I rode it everywhere and one day, for reasons now lost, my friends and I took some shaving cream and lathered the bike with it. Then we left it, and some hotel employe came along and threw out the bike as junk.

The employe admitted that. He told my father what I had done, and my father tried to tell me that what the man had done was perfectly reasonable, but it hurt anyway and it hurt all the more because I had to explain why I had covered the bike with shaving cream. You don't do that to things you want, I was told.

Anyway, Cooper and I talked about that and about some other things, and I told her about that bike. I slammed my fist on the table and said that this is why I wanted to write her story because it was about my old bike. But now I have done most of the writing and now I have worked it through the typewriter a dozen or so times and the only thing that comes through is the time I took something my son had made, out of some paper and some paper clips, and threw it away. It turned out to be a fort.

After lunch, I drove Cooper to the subway and she told me she felt as she had felt when her grandmother died - when you lose something valuable and you lose it forever. She said something else. She said it was good to talk about what had happened. I said nothing and thought instead of that fort and the person who had thrown out her music. We have a lot in common.