02/02/2012 17:52 GMT | Updated 03/04/2012 06:12 BST

Portobello Puff - Chapter 18

'Why are you so cheery?' says Geoff, glaring out of the window at a club-footed pigeon pecking at a half-eaten burger bun.

'No reason,' I say, gazing at a large bunch of green tea roses on Pam's flower stall.

'Well, stop smiling then,' says Geoff.

'Sorry,' I say, 'it won't happen again.'

Geoff and I are shivering at the corner table in Coffee Plant. It's so cold that Geoff's wearing his pyjamas under his clothes with the bottoms peeking out beneath his stained black trousers. We've spent half of the morning bickering about who finished the extra mature Cathedral City cheddar and now we've called a truce with a hot chocolate.

The other half of the morning was spent tackling a particularly tricky article about the brain and perception as part of the website's 'Mind Matters' series. I kicked off with a quote from Immanuel Kant "A man sees the world as he imagines it to be " (nothing like a quote from a chubby eighteenth-century German philosopher to add a little weight to an otherwise distinctly flimsy feature). Then I threw in some science stuff: how we only see 4% of what's happening around us at any given time otherwise the brain would go into meltdown; how that 4% is dictated by our worldview; how anything beyond this worldview is edited out ...). But when I tried to explain the plasticity of the brain and how it's possible to change our thoughts and therefore our perception, I had my own mental meltdown and called Wilson.

'Can you talk me through the plasticity of the brain?' I say. It's still so early in our 'courtship' that my stomach fizzes when I talk to him.

'Of course,' says Wilson, launching into an explanation, which whizzes way over my head.

'Were you always such a geek?' I say when he's finished.

'Oh yes,' he says proudly. 'Ask me another question. Make it really difficult.'

'Would you like to go out tomorrow?'

'Too easy,' he laughs. 'But the answer's yes - of course.'

Back in the café, Geoff's now staring at a heap of old cauliflowers by Linda's veg stall.

'Who the hell eats cauliflowers?' he says.

'I do,' I say. 'In fact I could have whipped up a tasty cauliflower cheese with the rest of that Cathedral City - if someone hadn't snaffled it all.'

I try to think of other possible cheese 'n' cauliflower combos, but then I notice Geoff's fingernails are bitten even lower than usual. It's weeks since he's mentioned his writing and any talk of replacing his old agent has long been forgotten.

'Look at that,' I say pointing at a shaft of sunlight that's broken through the clouds and is pooling on the pavement around the flower stall. For a moment the green tea roses, giant pink stargazer lilies and bunches of bright red tulips are lit up in a blaze of dazzling technicolour.

Geoff drags his eyes away from the browning cauliflowers to stare straight at the flower stall, still bathed in sparkling light

'Look at what?' he shrugs.

To be continued next Friday...