Every Mother’s Day I like to remind myself of my late mother’s way with words.

My favourite was probably her description of somebody who was a bit dim, which was: ‘If brains were dynamite, he wouldn’t have enough to blow his hat off.”

Which is ironic because this Mother’s Day I have been thinking a lot about things getting blown up.

Not that I am not a terrorist myself, you understand.

But I do feel the need to confirm this because my wife and I have been planning a big trip to the United States to mark her 60th birthday, and we have just got around to filling out our ESTAs.

That stands for Electronic System for Travel Authorisation, which all visitors to the States from the UK have to complete before they will consider letting you in.

You do it online and pay a few dollars, and as long as you answer all the questions to their satisfaction, they give you the OK.

The questions include one that I thought was a joke when I first heard about it.

But - sure enough - it really is on the form: ‘Do you seek to engage in or have you ever engaged in terrorist activities, espionage, sabotage, or genocide?’

Surely 99.99 per cent of people going to Graceland or Disneyland are not planning any crimes against humanity.

And even if they are, surely no actual terrorist, spy or concentration camp commandant would ever own up to it on a form.

So it begs the question of why they bother to ask in the first place.

One theory is that if you answer untruthfully (and you really are a terrorist), then that means you have obtained a visa by fraud, which would be enough to get you barred or deported.

As if terrorism is more of a grey area.

I was interested to find out if anybody ever answered the question with a ‘yes’, and of course they have.

They usually claim it to be a genuine mistake - as if they found the question a tricky one.

But I can’t help thinking that most of them do it for a joke.

If they do, the joke is always on them.

Because they invariably get taken at their word and are refused admission, sometimes at the considerable expense of having to rebook their holiday.

They presumably then also have to provide some kind of proof that they aren’t terrorists after all.

There is even the story of a three-month-old baby who was summoned to the US Embassy in London to answer questions about his terrorist activities, thanks to his family’s stupid answer.

I’m not sure which is more stupid: genuinely bungling, or trying to be a clever dick and answering ‘yes’.

But if the Americans ever decide to drop the terrorism question and replace it with another, I suggest they use these questions: a) what is your brain made of? and b) what is your hat size?