This hand swap optical illusion is wildly confusing the internet

There are some things that you either get straight away, or you don’t get at all.

The viral video below, in which Twitter user @kay_dera demonstrates a slightly mind-boggling hand swap trick, is the perfect example of this.

Pay close attention:

Did you get it?

Well, some people had it instantly.

Others, meanwhile, were less sure.

For anyone still wondering what the heck is going on, here’s a handy slow-mo.

Yep: all you have to do is straighten the hand at the back, and clench the one at the front into a fist.

Now go forth and impress the world.