I don't how it began, this love of writing letters, but I do know it has been with me for a long time, judging by the trunkload of old letters I have accumulated over the years. Sometimes I think it goes back to my godparents: Every Christmas, they sent the same gift, a savings bond and a silver spoon, engraved with my initials. It was a house rule that all gifts had to be acknowledged before the New Year or privileges were withdrawn. As soon as I reached the age of literacy and reason (judged to be 7 in those days), it was up to me to send a thank-you note. Although I was very grateful, it was hard to imagine just what one would do with a savings bond or a silver spoon, so I learned to write chatty notes that were about other topics.

And like most things that begin early, it would take a lot of de-programming at this late date to alter it. Not that I want to. I used to worry that I picked my friends by their willingness to write letters -- now I understand that I keep them that way.

Last year Americans exchanged 56 billion pieces of first-class mail, up five billion from 1974. I am sure it is all in phone bills -- most people do not write letters.

But letters provide a finer, truer conversation than phone calls: Nobody writes a letter interrupting every third sentence with "Gee, this is costing a lot of money." Phone calls are jangling, obtrusive -- cold abstractions. Letters are tokens of physical warmth.

Physical warmth, clearly, does not consist of: "How are you? What's new? Let's get together soon." The other day this letter arrived:

"Not very much is happening. I arise every morning, a possessed and driven woman and drop to the floor to do 60 sit-ups. My ex-husband always said I should reduce my stomach. Regardless of the fact that he should be roasting on a spit, the 60 sit-ups are probably not doing me any harm. I buy healthy food. I consume it at healthy intervals. Still, no real news . . ." h

A description of boredom, but never boring, the letter goes on to speak with urgency about everyday things, the secret theme of most letters. It will be accorded the ultimate compliments -- an immediate reply and a place in my trunk.

This ungainly piece of baggage, filled with letters I seldom read and cannot lift, is a mystery to me: Why do I keep them?

They go back 11 or 12 years, the oldest an invitation from a beau to hitchhike to the 1968 Democratic Convention in Chicago. I treasure it the way women of an earlier time saved dance cards from magnolia-blossom cotillions: "Want to thumb to Chicago in late August? . . . . I would not be surprised if there is a major catastrophe during the convention. And I don't mean Hubert Humphrey being nominated."

Love letters are like photographs in a forgotten album, they age too well, prompting thoughts of, "Was I ever that young? That in love?"

So many letters. A splendid postcard catches my eye, a lineup of 50 lifeguards on a Jersey beach. "We just opened the cottage. I hope you are planning to come Memorial Day."

I do not know if I made it that weekend; my many visits there are a blur of sunlit days: pure days, of hiking, running, swimming. Bone-weary days, capped with a glass of chilled white wine. Dinner is fish, clean sweet meat, filled with protein and ocean. That is a place to be, and just seeing that postcard produces a feeling that is not quite the same as being there, but an entrancement that is surely a close equivalent.

Of course, that's it. That's the reason I keep the letters. I've never been able to keep a notebook or a journal, something for the eyes of God alone. I never thought God would be interested. But these letters are an unwitting chronicle, an informal history, a diary by default of times past that I otherwise would run the risk of not remembering. The past lives vividly inside us all, sometimes more than we dare to admit, or care to confront. These letters are my bid to keep it breathing. t