I’m rubbish at English. My niece, who is studying medicine, asked me to explain the difference between paradox and irony. Her question was: “When you treat patients for cancer and it’s the treatment rather than the cancer that makes them feel ill, is this paradoxical or ironic?”

I hedged my bets and told her it was probably both, but bloody bad luck either way. Irony is one of those things you think you know, but it’s hard to put into words. It defies explanation, a bit like the taste of brie.

Teaching is full of paradoxes and the way we dish out homework is a case in point. A recent survey in my school flagged up a worrying statistic: the weaker kids who need homework the most are the ones who are given the least. And often the assignments we set them are pointless and inane. We conspire to fill up their diaries with simplistic tasks that require neither chasing nor marking. Hence their diaries are full of ludicrous commands such as “Cut out an advert” or “Bring in a jar” or “Print out Wikipedia”.

Sometimes, if we feel the need for more rigour, we might add “Get your parent to sign your diary to say ...” - but there the accountability ends. The reason we don’t write “None set” is that this goes against the school’s homework policy and our own principles of inclusion. But, since we’re expected to follow up missing homework, we cannily avoid setting tasks that might leave a paper trail. Paradoxically, while we’re short-changing our weaker sets by asking them to “Bring in some crisps”, we happily urge the already able to solve Fermat’s Last Theorem and precis Finnegan’s Wake.

Apparently the way we allocate homework tasks is not dissimilar to the way the NHS dishes out donor organs, where the consideration of “age and outcome” dictates who gets the kidney. If you’re young and fit, with a healthy lifestyle, you’ll get your sliver of liver. But if you’re in a class full of homework-abusers, your lifeboat has already sunk.

Another of life’s bitter ironies arrives with the festive season. It’s ironic - or should that be paradoxical - that other people’s happiness often makes us sad, and vice versa. Hence the TV advert featuring former X-Factorette Stacey Solomon blissfully crooning Driving home for Christmas as she pulls into the five-acre driveway of her vajazzled des-res in Dagenham makes me want to ram-raid the nearest Iceland store and chainsaw their hoisin duck Christmas trees.

I guess my envy is triggered by the fact that while our Stacey is driving home for a festive family party, I’m driving home to catch up on my marking. Still, at least the MS campaign offers a bit more solace; knowing that all those wistful X-Factor also-rans will be trapped forever in the amber of B-list obscurity is a much more cheering thought.

I have, of course, saved the darkest cosmic irony until last. My husband has been working in London this week, and while he’s been swanning around coffee shops in Soho I’ve been mopping up dog diarrhoea and treating a sheep with scald (imagine an ovine fungal toe infection but on an Old Testament scale). Just as I decided that life couldn’t get much worse, the telephone rang. My husband had been rushed to hospital and was hooked up to an ECG. He’d wanted an iPad 4 for Christmas, but he’s got atrial fibrillation instead. Thankfully, he’s safely on his way home now with strict instructions to rest.

Enjoy the schadenfreude; you can have this one on the house.

Anne Thrope (Ms) is a secondary teacher in the north of England.