I’m out on my bike. A gorgeous day – cold and crisp as a shiny new apple, fresh from the fridge. Wearing my helmet, of course, so can’t exactly feel the wind in my hair, but never mind.

‘Urrreugh.’

I can’t write it. You’ll have to imagine it. A sound like a gruff voice howling from a cave.

I look around – we’re in big-house-and-garden-world here – and through a set of iron gates see what looks like a bear climbing out of a drain. OK, so bears aren’t this colour – sort of greyish – but it’s what my mind says.

That’s minds for you. Here I am in leafy suburbia – quite near Liverpool, actually – and mine says, ‘bear’.

Anyway, I’m about to cycle on, thinking it’s a workman calling his mate, when I realise it’s an elderly man, lying on the ground, yelling, ‘Help me!’.

I swing round and pedal across the empty road.

‘Are you all right?’ I ask. Then, rather feebly, realising he’s not, I yell through the gate,  ‘Help, is there anyone there?’

I pull out my mobile. ‘I’ll phone for—’

‘No!’ It’s a sharp cry.

The man’s lying on his side, one leg under his ride-on lawnmower, its trailer spewing autumn leaves across the neat driveway. The steep grassy bank he was navigating rises above him.

A woman runs across the garden. I’m about to leave – he plainly doesn’t want me there – but she can’t manage alone and opens the gate to let me in.

I prop my plum-coloured, pride-and-joy-bike against the wall and it falls over. That’ll be her first scratch, I think.

Ah well.

We attempt to haul the mower upright – and fail. So we regroup, I try to drag him out while she lifts the machine a smidge, enough for me to get his trapped foot out.

She – the gardener – runs off to fetch a neighbour.

Elderly man, breathing hard, is still on his side and though it’s no longer trapped, his leg’s lying under the big machine.

Which is leaking fuel.

So, why don’t I call 999?

Well, because the man becomes really quite agitated at the suggestion.

But I’m worried by that fuel approaching his leg. I want to move it. But should I?

I try to remember what Anthro-man (a first aider) does.

Is he hurting, I ask. Can he move?

I risk it – pull his leg out.

A few seconds later he crawls up onto all fours, like a bear – well, a bear on its knees.

Does a bear have knees?

Whatever – it wasn’t such a silly image, after all.

He’s breathing in gasps. I ask, again, if he’s OK.

Sounding grumpy now, he mutters that he just needs oxygen and nods when I ask if it’s in the house.

The neighbour arrives. A calm man, he offers reassurance – and tea, which elderly man refuses. He’s all right, fine, doesn’t need tea. I’d love a cup, but my presence seems to upset the lawn-mower roller-over. So off I cycle, faster than usual, adrenaline-powered, to the sea.

The waves are tipped with a thin foam of pale steely grey, glittering in the sun, like an elderly head with a tightly curled perm. I don’t stay long, I’m too buzzed with the experience.

Cycling home I notice the houses more than usual.

The homes of longstanding residents mostly have wrought iron gates, small brick walls and shoulder-height hedges. Boundaries, yes, but not total exclusion. Or seclusion.

The newer owners – property tycoons, footballers, gangsters or who-knows-what – have high, brutal fences, electronic gates and video entry systems.

Money, seeking privacy.

It’s an odd thing, privacy. A friend tells me he worries about me baring my soul online. I suppose I have been a bit open lately. But, you know, it’s been like breaking a log-jam.

All my life I’ve been attempting to be perfect – I know, it’s impossible, but it’s the legacy of my upbringing. My father was terribly shy and desperate to maintain his privacy. Our house was never welcoming to friends and we had hardly any relatives.

And I realise now what a tension it creates, that desire to keep everything hidden, to present a perfect face to the world. To refuse help.

‘No, I’m fine thank you. Don’t worry about me.’

So British.

When I published a book I had to screw up my courage. I posted a biography online and – horror of horrors – a picture. And you know what? It was a relief.

Which makes me wonder about privacy on a bigger scale. The fuss about the NSA’s surveillance of the world and all that’s in it.

Do we need privacy? What do we need it for? Is it only criminals who need to keep things secret? Or people with odd predilections who don’t want their loved ones to know? Or Trolls exploiting anonymity to be nasty?

Celebrities, poor things, crave privacy. Fame has set them atop a cruel, fickle, revolving pedestal – too fat, too thin, genius, stupid, druggy, wife beater. Spin, spin, spin. Nothing too private for the prurient.

So I can understand their fences and their electronic gates.

But where would the man on the lawnmower have been if it wasn’t the day for his gardener to call, or if his gates had been like his next door neighbours’ – high, solid wood and electronically controlled? What if an escaped bear had found its way into his garden? Sorry, silly thing to say, it was just that image of a bear on its knees.

My plum-coloured bike, by the way, isn’t scratched, but the basket’s a bit out of shape. It’s no longer perfect – and it’s a bit of a relief.

Coming soon (but not necessarily next): more about privacy, the future and the Facebook generation