Back in the 1920s, lots of medical people were studying influenza. My great-grandfather was one of them. He, like many others, was frustrated that the culture dishes he was using kept getting contaminated with a mould that destroyed the bacteria around it. Annoyed that he couldn’t get the cultures to develop properly, he threw the dishes away and started again. This happened frequently, and like many other doctors he kept having to throw away these faulty cultures. One scientist, however, Alexander Fleming, realised that a mould that destroyed bacteria wasn’t actually a frustrating mistake, but a valuable discovery. He abandoned his original study, and started developing the mould instead. He called it penicillin.

And that explains why you’ll find Fleming in history books the world over, but my great-grandfather doesn’t get a mention. Fleming’s attitude to mistakes was that you could learn something from them, while my great-grandfather was too busy berating himself for messing up to see what was under his nose.

There are plenty more modest examples of this same principle. Right at the other end of the scale, I never truly appreciated the rationale behind filling up the car with petrol regularly until the time I ran out at 3am on a cold, wet night. That may sound like a flippant example, but it shows that we make mistakes at every level, and that’s how we learn. If you watch a toddler trying to stick two Lego bricks together, you’ll see that they can’t do it properly until they’ve got it wrong a few times.

Want another example? My second marriage is strong partly because I learnt from the mistakes I made first time around. I have a friend who messed up all through school and came out with no qualifications. It was his inability to get the kind of jobs he wanted, and knew he could do, that drove him to go back to college and work doubly hard to get great results. He’d never have done so well if he’d worked at school and then gone onto college without such drive and motivation. Some people might, but for him the mistakes he made early on became his motivation. Sometimes mistakes are the only way we can learn – and so long as we recognise where we’ve gone wrong, mistakes can lead us to great places we’d never have found otherwise.

The important thing about mistakes isn’t to avoid them but to make sure you learn from them. Avoiding them studiously is a bad idea, because you can only succeed if you never take any risks. As Einstein said, ‘A person who never made a mistake never tried anything new’. The more mistakes you make – so long as you’re learning from them – the more interesting a life you’re living. And that’s got to be good.