What is the meaning of life? Why are we here? Are we alone?
What's going on with these particularly shiny legs? Wait, what?
There may still be some philosophical questions about life that we may never know the answer to but it's simply a photo of a person's legs that has got much of the internet captivated this week.
Instagram user Hunter first posted the image online in September before it was reposted by Twitter user @kingkayden and retweeted by thousands of users.
He asked the simple question: "Are these legs shiny and oily or are they legs with white paint on them?"
are these legs shiny and oily or are they legs with white paint on them pic.twitter.com/7Z8e8F1JCZ— kayden (@kingkayden) October 26, 2016
Once the tweet was posted, the internet went absolutely crazy with comments and hilarious memes.
Once you see it you can't unsee it pic.twitter.com/5mREeJUhYV— bree (@msbreeezyyy) October 25, 2016
@kingkayden this took me way too long— marie (@flawlessflop) October 26, 2016
@DazzaBrownsword my head is spinning— George (@GeorgeWoodEFC) October 26, 2016
Then for some Twitter twitter users, it all became clear.
@kingkayden white paint. My eyes had to focus— Brwn Sgr (@Highdeflove) October 26, 2016
@kingkayden once i read it and understood it i see the white paint but at first i thought they were shiny— raven (@ohhshemixed_) October 26, 2016
@kingkayden Without a doubt, white paint. There are no light reflections or distortions on the legs as there would be if oiled.— Gregory Watton (@thewattonshow) October 26, 2016
@kingkayden i am very disappointed because i really thought they were shiny— gabe the fork (@CaptainKayden) October 26, 2016
It's not the first illusion to drive the internet crazy.
In April, a British Twitter user shared a confounding video of his son's toy train tracks, which appeared to show one track growing and shrinking depending on where he placed it. This is called the Jastrow illusion and has to do with the way the brain interprets curved segments.
My toddler's train track is freaking me out right now. What is going on here?! pic.twitter.com/9o8bVWF5KO— marc blank-settle (@MarcSettle) April 6, 2016
Since May, more than 7.5 million people have viewed this Imgur image of a couple hugging - mostly because their legs look impossibly (painfully?) intertwined. As commenters eventually figured out, the illusion springs from the design on the man's shorts. Wait for it...
In July, a Facebook user in the Philippines posted a photo of a floral carpet and challenged viewers to find the camouflaged phone placed on it. (That was shared more than 20,000 times, and liked by about 155,000.) A hint: The phone's patterned case is very similar to that of the rug, but they don't perfectly match up.
- additional reporting by Washington Post