The discussion with my client focused on whether or not it was possible to make meaningful change at his current stage of life. He felt that he was too old to change, while I was trying to convince him that it was absolutely still possible. To illustrate a point I drew an onion-like diagram on my whiteboard, with concentric (skin) layers representing the habits which we accumulate over a lifetime. In a final flourish I grabbed my whiteboard eraser to show that these habits can also be unlearned, only to find to my horror that I had accidentally borrowed a permanent marker.   While that particular example back-fired somewhat on me, it is indeed possible to change. At any age. We have all changed a lot in our lifetimes, and seen others do the same - for better or for worse. In fact - human beings are very good at learning, changing and adapting. The ability to do so is perhaps the most important of all the intelligences, and is certainly a big part of why we have been so successful as a species.    Why then does it sometimes feel so difficult to change? Often, the answer is ironically precisely because we are so good at it. We are in fact changing all the time - just not necessarily in the right direction. Whenever someone starts a new eating plan and sticks to it for a few weeks, they are indeed in the process of shaping a new habit. If however they gradually go off track and then wait another few months before trying again, the fact is that they will have spent a lot more time practicing the unwanted behaviour than they would have practicing the desired one. No prizes for guessing which of the two behaviours would have been strengthened the most.   In short, we are changing all the time. Our challenge is to spend proportionately more time practicing what we want, than we do practicing what we do not want.