On Wednesday, I took part in one of the Edinburgh heats for the Independent Sudoku Grand Master Championship. We were told that there were 125 heats in all, at 25 different locations around the country.

The session was run in exam conditions, although these were slightly disrupted by one of the hotel telephones ringing a couple of times. The invigilators were using a timing device to mark the completed papers so I selected the table nearest the timer at which to work, minimising the time it would take to get my paper to the machine once completed.

We were given four sudokus to complete and a maximum time limit of 45 minutes. The puzzles were reasonably hard but I raced through the first two. I stumbled on the second, realising halfway through that I had placed two nines in one column. I briefly pondered giving up there and then but that Paula Radcliffe moment passed and I recovered, switching a few digits round to correct my error and quickly finishing the grid.

The fourth puzzle was tough but straightforward. I found my mind wandering just as I heard one of the other contestants finish. This provided the push I needed and I doubled my speed, handing my paper to the invigilator a fraction of a second after the last number was written in. And then wondering, slightly paranoid, if I’d left any squares empty.

That was it. I picked up my goodie bag (including Independent stationery and a commemorative t-shirt) and headed to the station, still buzzing with adrenaline. This must be what Olympic athletes feel like, I thought, although with less sweat and muscle pain.

(Incidentally, if anyone spotted a letter in Friday’s Evening Standard about sudokus and crosswords and credited to “Will Howells, SE1” then yes, that was me. The hows and whys of that are a bit too surreal to elucidate.)