Research by Harvard psychologists show that the wandering mind is not a happy mind.

People are happiest when they are involved in what they are doing - living in the moment. That might be talking, listening to music, taking exercise. They found that people were least happy when they were resting, working, or using the home computer. Watching telly, doing the housework is neutral. Doing stuff builds our self-confidence.

Unlike other animals we spend a lot of time thinking about what is not going on around us. Most of us spend a great amount of time thinking about what might happen in the future, or raking over the past, they report. And it makes us feel bad.

How does this help us? Well, it reminds us that we should live in the moment. If you find you are ruminating about the past or worrying about the future, then getting involved with other people, going for a walk, working on a project. Anything where you can immerse yourself in the experience will make you feel much better. Find an interest that will engage you. And coming along for a session of cognitive behavioural hypnotherapy will help you if you have trouble with this idea.

Most of all, don't stay at home on the sofa.