The internet – and the limitless wealth of information it provides – is an immeasurably useful tool for more reasons that anyone can list.

Yet though there’s seemingly no end to the advantages it brings to our daily lives, it’s perhaps the fact that it’s a bottomless well of shared knowledge that makes it arguably the greatest invention of recent centuries.

There is no topic that you can’t read up on, no answer that’s beyond your reach if you know where to look. Mysteries that would have remained elusive in all the decades up to now can be solved quite literally with a few clicks of a mouse, a few stabs at a keyboard.

Over the years we’ve seen many old myths debunked online, just as we’ve seen life-hacks and helpful hints become common knowledge, whereas once they would have been wisdoms held by only a small few.

Have you ever wondered, for example, why your underwear ends up looking like it’s been stained by a bleach spot? If you have, you’re apparently not alone, with the question being posed online by women seeking answers.

And answers they found. As it turns out, said patches of coloring have absolutely nothing to do with your machine (as some have speculated). Dr. Vanessa MacKay, with the Royal College of Obstetricians and Gynaecologists, explains: “The vagina has a self-cleaning mechanism through natural secretions. It contains beneficial bacteria that serve to protect it.”

As per the National Institutes of Health, the usual vaginal pH ranges between 3.8 and 5.0, making it moderately acidic in relation to the naturally neutral pH level of 7. Read more below