Charles Moore's claim that one can be "trapped by wealth" has met with much chortling on Twitter and to calls for the world's smallest violin. If we cut out the narcissistic moralizing that passes for leftism, however, we should see that this is in fact a very useful phrase - in two different senses.

First, you can be trapped onto a hedonic treadmill. There are three pathways here:

- Many men of my age are stuck in unfulfilling jobs where they have to spout the sort of guff collated by Lucy Kellaway simply because they - or their families - have acquired expensive tastes. School fees and a demanding (ex) wife make downshifting tricky. As Nicholas Taleb says, "freedom is a very, very bad thing for you if you have a firm to run", so you want your employees to be trapped.

- If you grow up in a rich family, you regard an expensive lifestyle as normal and so need a high income to fund it. Worse still, you might feel the need to impress a demanding father.

- Most rich folk are surrounded by other rich people, which reinforces their perception of what counts as a "normal" lifestyle and so creates an urge to keep up with the Joneses. One reason why Sir Malcolm Rifkind touted his services to a conman was that he thought himself hard-up relative to his peers. I suspect that Blair's self-debasing money-grubbing has a similar motive; he's seen how plutocrats live and wants to join them.

Secondly, wealth traps you into a distorted view of the world. Charles himself gives an example of this. A Number Ten spokie claims that "millions of people" engage in the sort of inheritance tax dodging that the Cameron family did. But in truth most people need no more worry about inheritance tax than about maintaining their yachts.

As I wrote recently, this isn't the only way in which wealth warps perceptions. It causes you to under-estimate the hardship caused by what look to you like small cuts in welfare benefits. And it warps your sense of political priorities, causing you to under-rate the importance of improving the incomes of the worst off - even if you have benign motives. And it can breed a dangerous overconfidence.

For these reasons, Charles' phrase is correct and insightful. You can indeed be trapped by wealth. Which is one reason why inequality - and perhaps especially inherited inequality - is so pernicious.