I've had this my entire life and had absolutely no clue it was even a thing until today. Apparently, many many famous artists, musicians, and producers have it as well. This definitely explains why I've been so obsessed with music my entire life.

Here's the Wikipedia definition of Synethesia,

Synesthesia (also spelled synæsthesia or synaesthesia; from the Ancient Greek σύν syn, "together", and αἴσθησιςaisthēsis, "sensation") is a neurological phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway.[1][2][3][4] People who report a lifelong history of such experiences are known as synesthetes.

In one common form of synesthesia, known as grapheme-color synesthesia or color-graphemic synesthesia, letters ornumbers are perceived as inherently colored.[5][6] In spatial-sequence, or number form synesthesia, numbers, months of the year, and/or days of the week elicit precise locations in space (for example, 1980 may be "farther away" than 1990), or may appear as a three-dimensional map (clockwise or counterclockwise).[7][8] Synesthetic associations can occur in any combination and any number of senses or cognitive pathways.[9]

Little is known about how synesthesia develops. It has been suggested that synesthesia develops during childhood when children are intensively engaged with abstract concepts for the first time.[10] This hypothesis – referred to as semantic vacuum hypothesis – explains why the most common forms of synesthesia are grapheme-color, spatial sequence and number form. These are usually the first abstract concepts that educational systems require children to learn.

Only a fraction of types of synesthesia have been evaluated by scientific research.[11] Awareness of synesthetic perceptions varies from person to person.[12]

Difficulties have been recognized in adequately defining synesthesia:[13][14] Many different phenomena have been included in the term synesthesia ("union of the senses"), and in many cases the terminology seems to be inaccurate. A more accurate term may be ideasthesia.

 

Of all the conditions to have, this one is easily one of the coolest. I thought everyone's brains associated animated but not necessarily related images with every concept that filled their brain.

Marilyn Monroe, Mary J. Blige, Tori Amos, Vincent Van, Gogh, Billy Joel, Eddie Van Halen, Kanye West, Stevie Wonder, and Pharrell Williams all have been reported having this condition.