Let's look at the proof. 1926, Kurt Lewin, founder of social psychology, called this 'substitution'. 1933, Vera Mahler found, when it was acknowledged by others, it felt real in the mind. 1982, Peter Gollwitzer wrote a whole book about this and in 2009, he did some new tests that were published. It goes like this: 163 people across four separate tests — everyone wrote down their personal goal. Then half of them announced their commitment to this goal to the room, and half didn't. Then everyone was given 45 minutes of work that would directly lead them towards their goal, but they were told that they could stop at any time. Now, those who kept their mouths shut worked the entire 45 minutes, on average, and when asked afterwards, said that they felt that they had a long way to go still to achieve their goal. But those who had announced it quit after only 33 minutes, on average, and when asked afterwards, said that they felt much closer to achieving their goal. So, if this is true, what can we do? Well, you could resist the temptation to announce your goal. You can delay the gratification that the social acknowledgement brings, and you can understand that your mind mistakes the talking for the doing. But if you do need to talk about something, you can state it in a way that gives you no satisfaction, such as, 'I really want to run this marathon, so I need to train five times a week, OK?' So audience, next time you're tempted to tell someone your goal, what will you say? Exactly, well done.