I thought I was alone here.  I've ALWAYS wondered if my depiction of the color red... (or blue, or pink, etc...) is the same color you see.  

Ready to have your mind blown?  What if... The way I see the color red is actually a shade of green that you see.  Except that the 'green' is actually identified as 'red' to you.  Brain hurt yet?  Let's leave it to the pros to sort us straight.  I'm a huge fan of vSauce and this is a good one.  

Mind blown.