If you tolerate this

The aroma of frying onions is one of the greatest pleasures known to man. Even if you've just feasted on a banquet fit for kings, the merest whiff of a sizzling onion will make your mouth water to such an extent that your cheeks will explode in the manner of Vesuvius in 1906.

Raw onions, by contrast, are quite a different fettle of kish. They literally make us weep if we cut them and, in my case, if I eat them. Well, not weep so much as wander around for the next 24 hours as if Mike Tyson had come out of retirement specifically to land one on my unsuspecting chops. Chuck in a wholly disagreeable aftertaste which can last up to two days and there's only one reasonable conclusion I've been able to come to over the years - avoid raw onions at all costs. This is a pity because they're very tasty.

As vaguely sentient human beings, we are, I think, perfectly capable of distinguishing what's good for us and what isn't. In my case, fried onions = good, raw onions = bad.

However, just when you think that we've reached a saturation point of self-importance with our selfies and tweets and easy credit and toe nail parlours and... (I'm afraid there isn't room here for the whole, sorry list), yet another example rears its troublesome head.

A couple of days ago, I was passing a chemist's shop when I spied a very odd advertisement in the window.

"Test yourself to see which food intolerances you may have." Brilliant. How does this work, exactly? Little pills of hundreds of foodstuffs from avocado to, er, well something beginning with 'z'? You swallow one and if you faint or foam at the mouth, you have an intolerance. Are we in such desperate need of validation from any angle that we have to test ourselves for such things? I've got a raging intolerance of Jose Mourinho and Beyoncé's singing but I don't need to buy a test kit to know that; my eyeballs simply implode of their own accord at the very thought of either.

What happens when people buy these kits?

"Dave! Dave! Come, quickly! Look! I'm beetroot and carrot cake intolerant!"

"Wow! That's great love. I'm mushroom and lemon meringue pie. Actually, I got beetroot too but didn't want to steal your thunder."

It works like this: if you eat something and it makes you feel really bad, avoid it in the future.

Now then, what I wouldn't give for a cheese and raw onion sandwich for my dinner. Two days of malaise? It might just be worth it.