Here's one video that'll stop you in your tracks.
At first you'll think the train tracks are different sizes. But then your world comes crashing down around you.
The clip unsurprisingly went viral on Twitter. And as it turns out, these aren't just some strange alien train tracks.
When identical curved objects are placed next to one another, with the longer side of an object juxtaposing the shorter side of the other identical object -- as it is in the video -- the illusion is created.
So you can chill out and take comfort in the fact that you aren't just seeing things.