Wow, after all these years of tying running shoes, we’ve finally found out what that extra shoelace hole at the top is for.

It’s one of life’s little mysteries that we’d just learnt to deal with – until now, thanks to this illuminating video by the appropriately named Illumiseen.

And, given that the two minute explainer has now been viewed by almost 56.8 million people online since 2015, we’re guessing we weren’t alone in our ignorance.

So, here it is.

The extra shoelace hole is actually for preventing blisters and for stopping your foot sliding around while you run. This is how it works: Lace up your shoes as normal. Then, use the extra holes to create loops on each side of your shoe. The loops are then used to Execute. The. Lock. Aka crossing your laces and inserting them into the loop on the other side (doesn’t sound quite as impressive though). Then, tie your laces as usual to successfully complete the ‘lace lock’ or ‘heel lock’.

Minds. Blown.

Seriously, how have we never known this before now?

Tell your children, tell your friends, tell your Auntie Betty, tell the man in the street, goddamn it.