I'm currently considering getting some new glasses (to see through, not drink out of). I only really wear them for driving and cinema-going, but whether I'm behind the wheel of my Skoda, or sitting in a darkened room with a bucket of popcorn, I feel it's important to look my best, so I'm weighing up the pros and cons of a new set of face furniture. With that in mind, I went to Boots yesterday afternoon and loitered around the optician department trying on frames with absolutely no intention of buying. Mainly because I felt confident of finding them cheaper on the net. And sure enough, having admired myself in the mirror wearing the fetching pair above (which might not be rose-tinted, but still make me look good), I returned home and found them 40% cheaper online.

Unfortunately, having dug out my latest prescription, I discovered it's actually four years since I last read an eye chart, so with the distinct possibility that my ocular health has deteriorated since I met Lisa, I've booked myself in for a sight test tomorrow morning. It's at 8:55am, so I hope they allow for bleariness.

Anyhoo, when I'm not playing chess and trying to look intellectual in designer glasses, Lisa and I like to indulge in mentally stimulating pastimes like playing Richard & Judy's You Say, We Pay on interactive DVD. It was my Mum's Christmas present to Lisa. Which says a lot about both of them. I'm not saying we lead an empty existence, but having started after Coronation Street on Monday night, we were still playing 'You Say, We Pay' at 11pm.

It was mostly rubbish, due mainly to the fact that after each of my rounds, the DVD seemed to 'randomly' select all the same items for Lisa, meaning she basically just had to repeat all my answers to win, but it did raise an interesting point. Having already attempted to convey to me the celebrity John Barrowman with the words "It's the gay one", Lisa then surpassed herself by expecting me to identify an object from the clue "It's a tethered animal".

When I looked blank, she merely added "with horns". Obviously I guessed unicorn (who wouldn't), which led her to repeat (slightly impatiently) "no, it's a tethered animal".

The answer turned out to be goat. Personally I've only ever seen them roaming free on mountainsides, but Lisa insisted that an untethered goat is almost unheard of in this day and age, and that the word 'goat' should spring immediately to the mind of any sane person upon hearing the phrase 'tethered animal'.

Naturally I told Lisa she's a berk, and went to bed.

As it turns out, however, she could just be right. I've discovered this morning that The Tethered Goat is actually a famous mathematical problem, and in addition to that, The Tethered Goat Strategy was proposed by Sidney Blumenthal in The Guardian last year as a description of the USA's plan for Iraq.

So all Lisa needs to do is convince me she has an interest in current affairs, then explain this...


... and I'll let her have the points.