Flotsam, jetsam and lagan

'Grandma, did you know...?'

He bursts into the kitchen, eyes shining with excitement that he has facts to share. At six years old, he's thrilled with his own skill.

'Did you know...?'

His father used to start like that before launching into an elaborate description. He probably still does.

'...that whale poo is good for the 'vironment?'

'Really?' I say, wrinkling my nose. 'Isn't whale poo just poo?'

Actually I do know, I watched that episode of David Attenborough's before deciding it would keep the young one still for half an hour while I got dinner ready. But it's more fun if he tells me.

'Nooo!' He's pleased to have one up on me. 'No, it's made of really good stuff and the little animals eat it...'

'Yuk!' I interrupt in mock horror.

'They do and then the fish eat the little ones and big fish eat those fish and then the whale lies in the water with his mouth open and the big fish swim in and...'

'Boom!' I go, snapping my arms together like big jaws and making him jump.

'Yes!' and he giggles.

'But if the whale lies around with his mouth open, what about all the flotsam and jetsam?'

'Who Sam?'

'Flotsam – stuff that's floating around – and jetsam – stuff people throw off boats. Wouldn't the whale get rubbish in his mouth?'

'Oh no, you're not allowed to throw things in the sea. It's bad for the 'vironment and makes the seagulls and fishes sick. You have to put rubbish in the bin.' He's very serious and righteous.

'Ok, so the whale lies around with his mouth open and he doesn't get rubbish in his mouth. Then what happens?'

'The fish think it's a nice dark cave and they swim in and get eaten up.' He imitates my jaw-snapping gesture. 'Then... ' he's almost dancing with excitement. 'Then, he poos, lots and lots of orange poo. And all the fishes eat it like I said, so there's more fishes and more whales.'

'And then?'

'He dies.' He's matter of fact, unsentimental about this. 'And he sinks to the bottom of the sea, down, down, where it's all dark. And the fishes eat him.'

I can't deny it but I don't want to dwell on it. I still haven't found a way to tell my son about my diagnosis, so how on earth will I tell this lively boy that I'll fade away and leave him before his next birthday?

'So he becomes lagan,' I say, creating a diversion. I love giving him new words.

'Lagging?'

'Lagan. Things on the bottom of the sea, like pirate treasure and lost fish hooks.'

'Will Dad take me fishing tomorrow?'

It worked.

'You'll have to ask him. Now sit up, dinner's ready.'