I’ve always known that you don’t know what you don’t know, but now I’m learning that I don’t even know what I thought I knew. For example, I was listening to classical radio the other day, when the theme from “Peter and the Wolf” started playing. “Tchaikovsky!” I exclaimed confidently, congratulating myself on my encyclopedic knowledge of the arts, until the announcer patiently explained that it was Prokofiev. Of course it was; I’ve heard symphonies perform that work for as long as I can remember, but my knowledge of the composer was obviously contained in a part of the brain that was erased to make room for knowledge of the subclass code required to ring a $2 greeting card into the cash register.

A similar thing happened to me after law school, when I noticed that the part of my brain that once empowered me to make interesting conversation with promising new acquaintances of the opposite gender had been erased to make room for statutes of limitation, the rule against perpetuities and the formulae for calculating bonuses earned by Bay Area law firm associates. I guess it’s true what they say: “Use it or lose it.” It seems that regular reliance on computer spell-checking has reduced my spelling to a fifth-grade level, daily use of the cash register has left me unable to make change for a dollar without the written assistance of a receipt, and practical use of a calculator has been compromised by my inability to remember what needs to be divided into which to equal whatever.

And to think that I once handled multimillion-dollar legal contracts. It’s as if parts of my mind have become as flabby as my midsection, in need of some sort of mental corset or brain trainer or, like presidential candidates, constant use of a teleprompter. On the other hand, I retain an incredible amount of useless minutiae. Want to know who starred in the television series “H.R. Pufnstuf” in 1969? Wondering what the lyrics are to the Super Chicken fight song (I can perform this for you if you’re buying)? Curious as to the mother’s maiden name of that guy I dated 30 years ago? I’m a steel trap where these details are concerned, so why worry if I sometimes forget my own zip code and can never find my sunglasses?

Of course, my intermittent mental meltdowns are fodder for the technology industries, which exist mainly to make us all feel like doddering ancients. Nothing sounds sillier than people over 50 tossing around terms like “tweeting” and “Facebooking” and “Skyping.” I think a good rule of thumb should be that if you are of a certain age and you have heard of any device or application, or of anything at all of any kind whatsoever for that matter, you should just assume that if you know about it then it must already be tragically passé.

I particularly dread texting, and believe that there is a conspiracy among young engineers to transform what I typed into incoherent gibberish just to make me feel stupid. What laughs they must share,

sitting there in Cupertino by the server in the middle of the night, drinking Pepsi and eating Fritos, changing the word “nana” to “anus” in my messages for their own amusement. And they never tire of requiring me to update my passwords and PINs, just to confirm that dementia is looming. Apparently identity thieves have discovered my cat’s middle name, and so my passwords must be replaced with some constantly-revised combination of upper- and lower-case letters and numbers and colors and hand-signals to prevent penetration. I suppose I could write my passwords down and put them in a secure location, if only I could remember where that was.

On the bright side, my friends and I are mostly in the same boat. We sit around for hours patiently hacking away at conversational exchanges such as: “Did you see that movie last night? It starred the guy who was in that thing we saw in the theatre next to that restaurant we didn’t like.”

“The one near that place we used to go?”

“No, not that guy … the other one.”

Luckily, the theories of six degrees of separation, and of six degrees of Kevin Bacon (Google this, if people still do that), really do work, and we eventually remember whatever we were discussing, or forget that we were trying. After all, the secret to feeling smart is to surround yourself with people who are just as clueless as you are, and — as Gladys Knight, etc. recorded in 1989 on the Arista label — “that’s what friends are for.”

(Laura Rafaty is the owner of PennalunaNapaValley.com, a resident of St. Helena, an attorney and former theatrical producer, and an author and columnist. Read more at LauraRafaty.com.)