Have you looked inside your water bottle? I was shocked and disgusted by what I found in mine | Arwa Mahdawi

I stared into the abyss, and the abyss stared back – mouldily. This is what happens when you forget basic hygiene

In my 20s, I cohabited with a man who thought you didn’t need to wash towels because you used them when you were clean. This was someone, I should add, who graduated from both Oxford and Cambridge and now has a very high-powered job. (Not that any of that means you have an ounce of common sense, of course.) Anyway, I obviously teased him mercilessly about this. What a nitwit, I thought.

But now I have a terrible confession to make. I too am a nitwit. You see, about a year ago, I replaced my trusty clear plastic water bottle, which was super easy to clean, with one of the trendy brands made of stainless steel and silicone that everyone in my gym has. What with the gasket and the straw and the various bits you couldn’t stick in a dishwasher, it was a faff to wash. So I wasn’t very diligent about cleaning it. After all, it was just water inside, right? And water’s clean, right? I had put flavoured electrolytes in it a couple of times, but I didn’t think much about the fact that they are a tasty meal for bacteria.