And so it begins, the inexorable decline that means you have taken a step over the hill.

It's okay, I don't mean it. I can't even get up the flippin' hill. But I do suffer from the occasional small lapse in concentration and, sometimes, it goes viral.

A few days ago I walked into the supermarket with my bags for life and then came the terrible realisation that I wasn't wearing any make-up. I scrabbled in the bottom of my capacious handbag for something to rescue the situation – a Nivea lip balm and six ballpoint pens. Glossy lips and ink-blue eye liner? No. I decided to brazen it out. The good thing was, no-one was likely to recognise me because I am never, ever seen without make-up.

In fact, I won't even be heard without make-up. Occasionally, I am on the wireless early in the morning but, no matter what the hour, I wear foundation, blusher and mascara, live on air from my home...

You see, I am one of the Biba generation. It was the slightly scary teen culture of the late Sixties and early Seventies and required me to wear a great deal of black eye make-up, Yellow 1 Biba foundation and lipstick the colour of congealed blood. I must have looked like a slightly jaundiced zombie.

But I loved it, and for the past 47 years have rarely been seen in public without my face on, although I don't have Biba any more. The last time a complete stranger saw me naked from the neck up was probably when the anaesthetist put me under for my knee replacement, although I think I did risk a dab of rouge. Surgical procedures can make you look so washed out, can't they?

Now, in an historic first, I had to manage a supermarket shop without any artificial cosmetic aids. I decided speed was of the essence and darted along the aisles, even stretching to reach items on high shelves. Normally, I summon a tall (frequently male) shop assistant to help me, but with no make-up I didn't feel I could take the risk.

I sped around my familiar route and didn't linger over the reduced price cheese or pause to take advantage of the six-bottle wine offer. Avoiding all human contact, head down, I charged for the do-it-yourself checkout, which then proceeded to make life a misery with its endless demands. In Waitrose, the Voice of the Till (VOTT) keeps hurrying you up ('Scan the next item or press finish and pay'). In M&S it wants you to process your Sparks card before anything else, and in Sainsbury's the insistent VOTT asks in a very loud voice: 'Have you swiped your Nectar card?' 'Yes,' I snap back. Why are these voices all female? If a disembodied George Clooney asked me to do something – anything at all – I would comply. In any event, the most skilled of self-checkout customers is unlikely to get through a whole trolley without having to summon a member of staff to key in their magic number at least once, if only to authorise your bottle of gin.

I scurried back to the car and drove home without once (feminist alert) checking my face in the rear view mirror. I rushed into the house, slammed the door behind me and looked for my husband. I found him in the garden, tackling the bamboo with secateurs. He could see I wasn't happy.

'I went out without any make-up on!' I said.

'Oh, no,' he said, uncertainly clutching a stick of bamboo.

This was unexpected. Where was the: 'You look lovely just as you are, Lynne.' Eh?

The two-year-old grandson disaster zone we know as Wil is somewhat accident prone. It doesn't help that he creates 'obstal courses' in the sitting room and leaps from footstool to sofa, from sofa to seat cushion. He bruised his earlobe in one misadventure. He now has his own catchphrase: 'I'm all right.' This week he propelled a toddler trolley full of wooden bricks down the stairs. The noise brought everyone running: 'I'm all right,' he announced from the top step.

Later he ran over grandpa's foot with the trolley. 'Ouch,' said grandpa. 'I'm all right,' said Wil.