My wife Angela Gallagher taught me how to play Sudoku. She did it during one of our hospital visits when she was being treated for breast cancer. Not the happiest of times for either of us, really, yet there were moments. We would routinely spend five or six hours waiting, never knowing how long it would be, and she would play Sudoku on her iPhone. I can picture the seat I was in when she explained the rules and since that day I have played thousands upon thousands of games.

I still associate it with those times, even years later and when her treatment has been a success, but along the way I promise you that I have also learnt some productivity lessons. From a game. From a game Angela taught me in order to burn up some time waiting.

There is something to how you make decisions in this game where you don’t know where a certain number goes but you can make conclusions about it anyway. It’s got to be in one of these two spots, you’ll tell yourself, and that’s no use in that square but it does block out a line. Without knowing where it will go exactly, you do exactly know its impact on the rest of the game.

I think I’ve learnt from this that you don’t have to wait until you have a definite final answer, that sometimes you can draw enough of a conclusion that you can get on with something else.

But without doubt, this is the one thing I have really learned from playing Sudoku:

Walk away and come back later

I have struggled with a Sudoku puzzle, struggled and then when forced to go away to do something else, I’ve regularly come back and immediately seen the answer.

I have been of the school that says you work at something until it is done. But sometimes it’s better to stop, do something else, and then come back.

By the way, I’ve only ever played two Sudoku apps and the first one, the one Angela taught me on, is  no longer available in the App Store. But this one is for iPad, this one I’ve taken the screen grab from, that’s Sue Doku which is a just preposterously cheap 69p UK, 99c US. I’ve played this for hundreds of hours now, I can’t believe the pleasure and the productivity lessons I’ve got from a whole 69 pence.