If you need a little brain teaser to wake you up today, you're in luck.
The world's most dedicated puzzle fans and designers named this the puzzle of the year back in 2012, which should tell you how challenging it is.
All you need to do is fit the wooden square into the fabric bag. It sounds simple now, but you'll be scratching your head all day trying to solve it. Thankfully, the solution is included at the end of this video, but give it your best shot first.
I wasn't able to figure this out without help, but maybe you're smarter than I am!
That was tough, did you get it right? There are more challenging puzzles on Fleb's YouTube channel, but be warned they can be pretty aggravating!
I think I'll stick to jigsaw puzzles from now on.