How do such errors happen, in our enlightened, knowledge-rich times? We can say straight off that they occur with appalling ease and regularity. Academic achievement and career success seem to provide no vaccines. Otherwise intelligent people daily and blithely make the move.

Given that it is about the single costliest mistake any of us can make (it places rather large burdens on the state, employers and the next generation too), there would seem to be few issues more important than that of marrying intelligently.

It’s all the more poignant that the reasons why people make the wrong choices are rather easy to lay out and unsurprising in their structure. We ruin our lives for reasons that can be summed up in an essay. They tend to fall into some of the following basic categories.

off alarm bells in any prospective partner. The question is just where the problems will lie: perhaps we have a latent tendency to get furious when someone disagrees with us, or we can only relax when we are working, or we’re a bit tricky around intimacy after sex, or we’ve never been so good at explaining what’s going on when we’re worried. It’s these sort of issues that – over decades – create catastrophes and that we therefore need to know about way ahead of time, in order to look out for people who are optimally designed to withstand them. A standard question on any early dinner date should be quite simply: ‘And how are you mad?’

 Being single is so awful

One is never in a good frame of mind to choose a partner rationally when remaining single is unbearable. We have to be utterly at peace with the prospect of many years of solitude in order to have any chance of forming a good relationship. Or we’ll love no longer being single rather more than we love the partner who spared us being so.

Unfortunately, after a certain age, society makes singlehood dangerously unpleasant. Communal life starts to wither, couples are too threatened by the independence of the single to invite them around very often, one starts to feel a freak when going to the cinema alone. Sex is hard to come by as well. For all the new gadgets and supposed freedoms of modernity, it can be very hard to get laid – and expecting to do so regularly with new people is bound to end in disappointment after 30. Unquote