I tell students that even if they don't like math right now they can use math as a brain-sharpening tool - a tool that not only builds the foundation for a great career but that also builds self-confidence no matter what they choose to do with their lives.

The choice between a Labour government and a Tory one is sharpening minds.

In the future when Microsoft leaves a security-flaw in their code it won't mean that somebody hacks your computer. It will mean that somebody takes control of your servant robot and it stands in your bedroom doorway sharpening a knife and watching you sleep.

Training is such a vital part of preparation for a game you really do train to play. It tops up your ability like sharpening a carving knife. You can get away with not doing it for a while as long as you have reached a certain standard of fitness.