Apparently, so I read recently, because I've been on holiday and therefore reading look out world, if, in an interview, you give too many reasons for a piece of past behaviour you will be suspected of faking. One reason should be sufficient. You should be confident enough to give one only.
But, I scream quietly, show me a person who claims to act out of some purity of motive and I'll show you a liar. Rain is always good news for umbrella manufacturers. But do they wish to make us poorer or drier?
Good leader or not I am now convinced that Gordon Brown's motivation is not simply hanging on to power at all costs, but also to lead the country through a crisis. Opinion polls suggested a massive swing to the right when Brown under-achieved in his first year. I doubt there will be a corresponding swing back now he has over-achieved, or at least - achieved. But I am convinced he is motivated at least as much by compassion as power.
This is not a party-political broadcast. I am a floating voter and have been for the best part of two decades now. It is a call to allow a politician without the blessing of a hugely charismatic personality to be judged on his achievements alone. As we watch the death-throws of the US presidential campaign we should rejoice that we allow some discussion of matters of substance on the trail here rather than three soundbites, two clothes budgets and a centrefold.
By the way I've now consigned all my pithy sayings to the loft. Up there it's axiom attic.