I'm usually annoyed at the changes in my mental infrastructure. Blown fuses. Memory parity errors. Slow reboots. Noisy signals. No BSD yet, but that's only because I'm not running Windows. At least I hope I'm not. I don't see the changes, of course, only their effects, and from the effects I infer the underlying causes. I hear sounds, but can't translate the sounds into words or the words to meanings. I forget a well-known fact. A few weeks ago I forgot my zip code. At least I think I did. But I'm not sure it was my zip code I forgot. Maybe it was my telephone number. Maybe it wasn't a couple of weeks ago, but a couple of months ago.