I once heard a the­ory about the first re­la­tion­ship that oc­curs af­ter a big re­la­tion­ship ends. It’s called the 90/10 rule. The the­ory goes: what­ever the cru­cial 10 per cent is that was miss­ing from your part­ner who was oth­er­wise to­tally right for you is the thing you look for in the fol­low­ing per­son. That miss­ing 10 per cent be­comes such a fix­a­tion that, when you do find some­one who has it, you ig­nore the fact they don’t have the other 90 per cent that the pre­vi­ous part­ner had.