But that's already out of date. While you were trying to get out of bed yesterday morning, Mr Hancock memorised a 480-digit binary number after 15 minutes of study. He recalled 91 numbers, in sequence, out of 120 that had been read to him. He did the card trick again, immaculately (he can now do it in 55 seconds).
And by lunchtime Mr Hancock had been awarded a large silver cup as Ernst and Young Student Memory Champion of 1993, having scored more points than those of the second- and third-placed competitors put together, a fact he is unlikely to forget in a hurry.
Mr Hancock is a reassuringly normal chap. His glasses are of average thickness, and he is reading English Literature, not quantum physics, at Oxford University. In his spare time he works as a presenter for a local radio station, and he hopes to go into broadcasting. He doesn't even sneer when you ask him his age again - 21 - having forgotten to write it down the first time.
But he is some sort of genius. James Lee, who came second in the competition, said yesterday in awestruck tones: 'What Jonathan has achieved is pretty close to what Dominic O'Brien achieved in the International Memoriad '93'. (Mr O'Brien is, of course, the world champion 'mnemonist', memoriser of 35 packs of playing cards, and author of How to Develop a Perfect Memory.)
Mr Hancock says that developing a perfect memory is pretty easy, really. With cards: 'Each card has its own coat, and I memorise them as pictures. Then I tell myself a story between the pictures of the different cards.' Numbers are visualised as pictures, or objects, too: Mr Hancock has a visual image of every number between 1 and 99. He places the images in order round an imaginary room, which he can then tour and 'collect' them.
Tricks such as the 480-digit binary number are the easiest 'because it seems the hardest. I . . . convert a row of 30 numbers into five two-digit (decimal) numbers, and remember those. It's pretty simple really, but you have to be quite fast at conversion in and out of binary.' More difficult, he says, is memorising 200 nouns in sequence - it is harder to create a picture of them. Most remarkable, says Mr Lee, was Mr Hancock's remembering 91 of the 120 spoken numbers - the next best was 34.
The champion says he did not train particularly hard - just 'two packs (of cards) a day for the last month'. Physical fitness is also important: mens sana in corpore sano still applies.
The third-placed competitor, a seemingly sane and happy Natasha Diot, 16, from Ashford in Middlesex, took up memory techniques to help her with exam revision - 'it's very good for my French vocabulary'. James Lee read a book by Tony Buzan, the mnemonist's guru, and subsequently shocked his family with seven O-level grade As and three Bs. All the competitors are convinced that their skills are useful in real life - one of Mr Hancock's specialities is memorising 100 faces and names in 15 minutes flat.
Which makes it pleasing to record that, when the competitors all went off to lunch, Mr Hancock left behind his Student Memory Champion of the Year cup.