And I don’t mean perform favours for your boss. What I mean is that sleep will help make you money.

When I was about 15 I went to bed completely unable to translate some language homework. In my sleep I translated the whole thing and woke up being able to write the English without any problem. There are many decisions that we make when in the land of Nod that we may not even know we have made.

Then there is that time just between consciousness and unconsciousness (do they call it Theta state?), when I believe some of the best and most insightful decisions can be made.

Recently I was lying in bed in the morning without having fully woken up, when I realised in a flash that we were making a big mistake and had to change the format of one of the stores we were in the process of building (we had decided to experiment with self-service counters). Although my Theta-insight meant we had to pay for the changes in cash and delays, it just had to be done. And Henry agreed.

Now it had also been my idea to build it that way in the first place. So what was the difference between my mindset when I made the original decision, and my mindset when I realised those plans were wrong? In the first instance, I made a rational decision. Based on spreadsheets and theoretical assumptions. When I made the decision to scrap the plans, I was under my duvet without a laptop (no, really) and hadn’t even made a conscious decision to think about it.

My friend Ed told me that people make decisions in one of three ways: rationally, emotionally or intuitively. Malcolm Gladwell explores this in 'Blink', but it's interesting that he doesn’t (I don’t think) explain it quite that way. It would be easy to think that emotional and intuitive are similar, but they're really quite different. When you are making an intuitive decision, you are actually free of any emotional distractions. I believe, having tried to understand how I make decisions, that the brain makes an intuitive decision and then immediately post-rationalises the decision in order to feel like it is really in control. To create a map of the world that keeps us sane.

Another friend (a partner at Bain called Richard) told me of an experiment where they gave someone a buzzer and said: 'Here is a buzzer. Buzz it whenever you decide to. You have three minutes and you can choose to buzz it as many times as you like and whenever you choose'. When they tracked the electrical responses in the brain, they found that the intuitive part of the brain made the decision and then the rational part responded afterwards, to post-rationalise.

One of the reasons people become entrepreneurs, I think, is that they make intuitive decisions and then want to get on with making it happen. Hell for these people is having to spend many committee meetings presenting their ideas with PowerPoint presentations until everyone is convinced. That is like putting them in prison. But to make those intuitive decisions you need to be in a ‘good place’. Like bed for example. That seems to be a good place.

So when your husband or wife kicks you to get out of bed, just explain that you should not be stirred - you are in the middle of making your fortunes.