Things suddenly grab public attention and go viral for all sorts of reasons. Sometime it’s because a story involves a beloved (or notorious) celebrity, and sometimes it’s because it’s involves extraordinary everyday citizens. Sometimes it’s just because there’s a cute animal, and other times it’s a particularly heartwarming and inspiring story. Our favorites, though, are probably the ones that tease our brains, challenging our perspectives and making us really think. That’s right— we’re talking about optical illusions! Check out the latest one that’s blowing people’s minds.

One of the most impressive things about this one? It’s so simple. Just a few simple bars make up this brain teaser, and yet it’s super tricky. Take a look, and tell us how many bars you think there are. We’ll wait.

Finished counting? Good. Now raise your hand if you counted seven. No? What about eight? OK. Take another look and try counting in the opposite direction you did before.

Did you get the opposite number that you did before? It’s crazy but true: most people who count the bars while moving from the top will get seven, while those who start at the bottom will get eight. Even crazier? The actual number. It’s neither seven NOR eight.

It’s SIX.

Yes, believe it o not, there are only six bars in that picture. Can you see it now? Try starting at the top, and count the first five. The bars you think you see after that are actually disconnected lines, and there’s really a gap until the last and sixth bar. Our brains are so determined to make connections and form pictures that they’ll see bars where they don’t exist, just to keep a pattern going.

So be honest— how many did you count? Do you see the six, or are you still convinced there’s seven or eight? Did you get another number entirely?