You've got mail, I've got mail, we've all got mail. In its own right, it's pretty handy stuff, a high-tech tool that ordinary human beings can use without too much trouble. But after the first 5 megabytes or so of messages, I began to get something else, something much more low-tech and old-fashioned: the closest thing to the journal I've never bothered to write.

It all started when I figured out how to get my Eudora e-mail program to file my outgoing messages to friends into the same mailbox as their incoming messages. I wanted to avoid telling the same story to somebody twice, and the program seemed to run better when its outbox file wasn't the single largest item on the hard drive.

Four years later, the messages have gone from the dozens to the thousands and it's all become a sprawling mass of text: At the work account alone, I've got more than 4 megabytes' worth of mail in the "Friends" mailbox. (To put things in balance, there's 19.4 megs in "PR.") Apparently I'm not the only person with this curious habit, to judge from one of the Internet's ranking e-mail gurus.

"I know many many people who keep all their outgoing email," e-mailed Steve Dorner, who wrote the original version of Eudora in 1990 and is now a vice president of technology at Eudora's publisher, Qualcomm. "Some of them just let it pile up, others file it into the same mailboxes they normally would file incoming mail on the same topic. Still others stratify their mail by month, and 'roll over' all their mailboxes, incoming and outgoing, once per month."

(He isn't one of those people, however: "I personally, being a 'neat freak,' very seldom keep anything at all," he wrote.)

Clicking through one's old e-mail is, to be sure, a peculiarly solipsistic way to spend one's time. A little dorky, even. But it's also enlightening. Having this accumulation of e-chatter is different from keeping a boxful of letters in a closet: It's all there, waiting to be sorted, re-sorted and browsed through. I can list messages by sender, date or subject. If I feel like, say, tracing the crash-and-burn trajectory of a failed relationship, it's easily done--too easily done, actually. Or I can hit the "Find" button to locate that conversation I had about, say, computer fonts or cookie recipes in 1996. (This, incidentally, is why I wouldn't ever want to rely on AOL or one of the Web e-mail services: It's painful to manage this much message traffic with their tools.)

The whole process is not to be done too frequently; it's too full of those what-was-I-thinking, smacking-self-in- forehead moments. But at best, it's also akin to flipping through a photo album, albeit one that includes the good and bad parts. There are giddy post-vacation e-mails and forwarded jokes that were actually funny at the time, plus the occasional dispatch about street crime or deaths in the family, all spaced between much the same sort of thing from other people. I've got the first message I ever received from my brother and the last one I got from my dad, sent a month before he died (subject header: "Sign Off," about losing his work e-mail account in the wake of retirement). All waiting in one folder on my computer. People have talked a lot about e-mail as somehow lacking the personality, the humanity of handwritten letters. That is utter nonsense.

A lot of the story of technology revolves around unanticipated consquences. Many of them are not so good: Cheap long-distance leads to dinnertime calls from people selling cheap long-distance. This is one of the better ones: Buy an inexpensive way to send text messages back and forth, get a window into your own head.

To add to all this unintended record-keeping, since the summer of 1995 or so I've been toting around one electronic organizer or another--most of which have eventually had their data poured into my computer. Back when I carried around week-at-a-glance planners, I'd toss out the past year's schedule in January, but I've never bothered to delete old calendar files on my computer. So now I can not only read what I was saying on, say, Sept. 17, 1997, I can also see what I was doing and where. I can flip through a vaguely panicked series of notes I took on an Newton MessagePad when I went apartment shopping in the summer of '97, the crunch of appointments in the two weeks before every Christmas and the event-free weeks that shout "Vacation!" (Thanks to the Palm III I'm toting around, I can do the same thing anywhere outside of the house.) Browsing through this info feels a bit like looking out the airplane window and figuring out what kind of place it is 30,000 feet below: "Yup, must have been a lousy month back then."

Finally, since the beginning of 1997 I've been throwing all of my financial transactions into Quicken. Crack that open and I've got every credit-card transaction and ATM withdrawal since the beginning of 1997. I only wanted to figure out where I was throwing away my money each month, but now it helps me trace my life back further. I can tell when I started spending too much money in yuppie-food markets, how many days I've been able to go between cash-machine hits, where my CD shopping has shifted over the years and spot poorly budgeted months when $100 has to last until the next paycheck. Marketing types would, no doubt, love to vacuum this information into a very large database somewhere.

What's really scary, however, is where this will wind up in 10 or 20 years. I've been using e-mail for only five years, and Quicken for less than three. Will I have to run one of those bulk-erase magnets over the hard drive to wipe this data away when I get rid of the computer? Do I even want a rearview mirror this big? I hope something I write between now and then helps me figure out the answer to that.

Living with technology, or trying to? E-mail Rob Pegoraro at rob@twp.com.

Rob Pegoraro will be hosting a live Web discussion at 1 p.m. today with AOL senior product manager Gary Lampal, who headed the team that built AOL 5.0. To participate, go to www.washingtonpost.com.