Everyone loves a good optical illusion and figuring out just how it works.
However, it's not always possible to replicate them in your own home but a new challenge has people doing just that.
A mind-boggling but relatively easy hand trick first shared in a now-viral video by Twitter user @kay_dera sees her seemingly punch through her own hand without any trouble at all.
Confused? Take a look at the below video and you'll see what I mean. Warning: There is an NSFW soundtrack in the below clip.
At the time of writing the clip has been viewed over 3 million times and people were completely perplexed as to what was going on.
Others though perfected the art of the trick almost instantly.
Some people are being very helpful in their explanations.
However, we think this guy's effort is the best that we've seen.