It's the greatest battle the internet has ever known.
Okay, that may be a slight exaggeration.
It all started with a plain white t-shirt and iconic Life Magazine cover.
The Notebook hunk was spotted wear a t-shirt featuring Macauley Culkin wearing a Ryan Gosling t-shirt, when Ryan Gosling originally wore a Macauley Culkin t-shirt.
Get it? Good.
Some crafty online users with questionable Photoshop skills have taken this competition to the next, more epic level.
The essential Gosling/Culkin Timeline:
March 22, 2013: Ryan Gosling wears a T-shirt of Macaulay Culkin's LIFE cover.
May 12, 2014: Pizza Underground post a photo of Macaulay Culkin wearing a t-shirt of Ryan Gosling wearing the T-shirt of Macaulay Culkin and generally being the mega chill dude that he is.
May 13, 2014: Someone on Twitter unconvincingly Photoshops an old photo of The Gos implying that he has within 24 hours somehow sourced a T-shirt with a print of the Macaulay Culkin wearing Ryan Gosling wearing Macaulay Culkin photo.
May 14, 2014: Dispensing with any pretence of authenticity, someone else even more dodgily Photoshops a random photo of Macaulay Culkin wearing a tee that depicts Ryan Gosling wearing a T-shirt of Macaulay Culkin wearing a t-shirt of Ryan Gosling wearing a T-shirt of Macaulay Culkin.
Additional reporting by Christopher Hooton, Independent.co.uk