I recall a colleague of mine being deeply hurt and upset once because he’d been excluded from a meeting he felt he ought to have been asked to attend. He spent ages worrying about why he’d been omitted, not liking to ask the Chair because he didn’t want to come across as petulant, or needy, or something. We all told him not to worry about it, but he got himself into quite a state. Anyway, come the meeting, about five minutes in, the Chair asked why he wasn’t there. We explained he hadn’t been included, and of course it turned out there was some technical reason why he wasn’t on the Chair’s email group, only she hadn’t noticed.

The thing my workmate had never considered, in all his fretting about why he wasn’t wanted, was that it was simply an accident. He assumed the Chair had thought through who was invited, but in fact she simply hadn’t thought at all. That was a possibility he, ironically, didn’t think of.

It’s surprising how often this kind of thing happens. This Rule is titled ‘Some people just don’t think’, but in some ways I could have called it ‘All of us don’t think sometimes’. Not very grammatical but perhaps more accurate, because we all do this from time to time. How often do you catch yourself about to miss someone out, or fix a date for a party completely forgetting that one of your close friends told you they couldn’t make that date? It’s so easy, and yet it’s often the last explanation we think of when we’re on the receiving end.

Sometimes it’s nothing but an understandable error with unexpected consequences, as was the case with my colleague. At other times it’s what we term ‘thoughtless’ – in other words, the person really should have been thinking, and was out of order in not making sure they got things right. Nevertheless, it’s still unintentional, and thoughtlessness is not malicious.

I once made someone a birthday cake completely forgetting they were gluten intolerant. Stupid, stupid thing to do and I could have kicked myself a dozen times over. The worst of it was, for some reason they thought I’d done it on purpose and got upset. It took me ages to explain that I simply hadn’t thought about it. They believed me in the end but I was still furious with myself because obviously I felt I should have remembered.

When you’re trying to understand someone’s motivation for doing something that doesn’t seem to make sense, always consider the possibility that they simply didn’t think. It’s so much easier to take than being deliberately snubbed or offended or excluded or riled or upset, and so often the true explanation.