As you'd expect, this trait was more noticeable when he was a deputy, and a colleague from those days tells of entering Peter's room and admiring a row of neat box files, one of them labelled "non-swimming".
"Just for a moment," he recalls, "I thought Peter, having organised the whole of the known world to his liking, had started to tackle the negative dimension."
My own memory of Peter is of catching him in the corridor to ask him something important. I received a breezy, on-the-hoof acknowledgment and, in time, I assumed he'd forgotten my request. But he hadn't. Within a week he'd acted on every detail.
If he had forgotten, he could surely have been forgiven. We should all, leaders and led, know better than to raise important issues with people when they are on the move and thinking of something else. It's a recipe for misunderstanding and serious error. Indeed, in my experience it has led to:
* a class being unsupervised for half a morning
* a child missing the chance of a free place on a residential trip
* a teacher missing out on a short-notice job interview.
What's to be done? A special needs co-ordinator I once interviewed had her own answer. Sencos are often the most accosted teachers of all. On the one hand, they are seen as the gateway to salvation for everyone with a problem, but at the same time they are not usually senior enough to frighten people away.
"I couldn't take three steps without being stopped and told stuff I was supposed to remember," she says. "So now I carry a pad and a pencil everywhere, and I refuse to listen to anyone from the head down with a query unless we both have time to stop and agree on the note I'm making."
As she acknowledges, this is one of those apparently simple solutions that actually calls for steely determination.
But, she says: "Stick to it, and eventually everyone realises that it works, and it's to their advantage."
But how, you wonder, did Peter Guggenheim do it?
Common sense says he went straight to his room and wrote it all down. But he's always been a hero of mine, and I prefer to believe in his flawless memory.