I had something to say on the subject and the touch typing I learnt at my local TAFE meant my fingers were flying. Typing at speed can still impress my sons. When they were young it used to dazzle them - one of the few things that could reliably achieve such a state, along with being able to see out of the back of my head to know they hadn't brushed their teeth or washed their hair, despite a 20-minute shower.

Mother: "Your head is bone dry and your hair still reeks. You didn't wash it. Did you even get wet?"

Son, thinking: "How does she do that?"

Mother: "If you don't get back under the shower and come out smelling like flowers I'll go back in there with you because you're smelling the house out."

Son: "Noooooo!!" before rushing to the bathroom and slamming the door.

Anyway, I was punching out the words last week and had reached about 600 - with, say, 500 or so words to go - when I started the following sentence about tradies and the kinds of utes they drive where I live, with dings and bangs worn as a badge of honour.

"Every so often these real-ute tradie owners will hose their utes down but the interiors remain true tradie - dust on the dash, food wrappers and empty drink containers on the floor, pens and bits of paper here and there, sometimes ciggies, and a .....," I wrote.

And then my brain stopped.

Now the brain is a wonderful thing. The average human brain weighs about 1.5 kilograms, has two parts, about 100 billion nerve cells, or neurons, and one trillion supporting cells that stabilise the tissue. How big is one trillion? Slightly more than the number of times you'll yell because your children haven't brushed their teeth, washed their hair or taken their dirty clothes to the laundry.

The brain gets messages from our body and sends messages back. To reduce a complex and extraordinary process to its basics, those messages involve information flowing from neuron to neuron via synapses which bridge the spaces between them.

Our brains are so extraordinary that we have something called a National Committee for Brain and Mind, once headed by University of Newcastle Emeritus Professor Patricia Michie. She was also the inaugural chair of the Australian Brain Alliance, which sounds like the kind of group that would have a fantastic knees-up at year's end. And I don't think we have a National Committee for Knees, or Noses. Just saying.

Anyway, back to my brain freeze.

I was writing about the front interior of a tradie's ute when it happened. Neurons and synapses had fired up and communicated without interruption for half an hour or so, and then the flow came to a screeching halt. A neuron fired, a synapse went AWOL, and the flow stopped just when I reached a description of a ute's dashboard, and specifically the thing beneath the dash on the left-hand side - the little cupboard in the front of your car. Yes. That's exactly what I came up with when my brain shuddered to a halt and I needed the word for that thing, the little cupboard.....

Then this happened.

Mother in phone call to middle son, a tradie, with a tradie's wondrously colourful flair for language: "Okay. I don't want you to comment. I'm old and tired and in a hurry so can you tell me, what is the name of the little cupboard in the front of a car?"

It takes a fair bit to leave my tradie son speechless.

When I nearly killed us both while trying to get off a roof a couple of years ago, and used his body as a way of softening the fall, he was speechless for a few seconds, before becoming very speechful when he was sure we'd both survived without injury.

He was speechless for about the same time the other day before becoming very speechful again, and slightly fearful, as if he was staring at a future where these kinds of calls are regular things.

Son: "Oh my @#!$&% God. I can't believe you just said that."

Mother: "Shush. Just tell me what it is."

Son: "Glovebox. Oh my God. Wow. How can you not know glovebox? Where on earth did you get little cupboard?"

Mother: "I don't know. That's the problem. The second I thought little cupboard I was stuffed. You can't get to glovebox, which is a weird word anyway when you think about it, if your head says little cupboard."

Son: "I'm going," he said. "I'm going to forget this call even happened."

And he hung up. I didn't even get a chance to mince "Mummy loves you," which is guaranteed to get him running in the opposite direction at warp speed.

Then it happened again. I quoted the Business Council of Australia chief executive, Jennifer Westacott, about the "cultural and financial bias that treats VET (vocational education training) like a second class citizen", except I didn't get to Westacott on the first go. I typed Jennifer and the synapse went AWOL again.

Now Jennifer Westacott isn't some anonymous powerful person for me, but a high school classmate. She was Jenny back then, hysterically funny, and a co-conspirator at times when lessons were less than engaging and we decided to rev things up a little.

So I shouldn't have had a mental block about her surname. But I did. I came up with Armitage. Why? I have absolutely no idea. I put it down to a synapse misfiring and sending me down a pathway that ended with the name of a person I wrote an article about in 1987.

The only comfort is that at least I had the right number of syllables. A quick Google search solved the problem, but it was disconcerting.

Was this the first sign of something terrible? I'm staring down the barrel of 60 and I'm now a grandmother but does age really hit this quickly? One day firing and the next day unable to think of the word for that thing in your car at the front... the little cupboard thing?

I did a Google search before rushing off to the doctor and lo, found relief.

My little cupboard in the front of the car and Jennifer Armitage moments were probably not portents of terrors to come but "tip of the tongue states", or TOTS, where there's a mismatch between the "meaning clusters" and "sound clusters" in the brain and your neurons and synapses take a detour instead of following the right path.

That might be too simplistic an explanation but really, does it matter? All I needed to know was that it's normal. We experience it once a week on average and, as we age, once a day. And if I remember that, I can't wait to tell my son.