Disclaimer: this fic is based on my own experiences with synesthesia, and is not meant to represent how others with synesthesia view the world. Also, I have never been professionally diagnosed, but then again, I'm not sure how many people actually are. I have, however, done some extensive research and come to the conclusion that I have it, given the way I view the world. Enjoy, and if you have any questions regarding my synesthesia, feel free to pm me about it!
Jack has synesthesia. He doesn't tell many people, and prefers to ignore the colors, because they can become overwhelming.
Sometimes.
Other times, though. Other times he lets the colors wash over him in waves, and basks in the beauty of the sounds he hears.
He's trained himself to barely process names, to just let them become sounds in his minds. He's done this for as long as he can remember, and didn't realize that the world was just a bit different for him than it was for most people until he was a teen, and someone told him that most people didn't get an impression of a color when they thought of a letter or heard a name.
He doesn't like to tell others, because it's an odd thing to say. And, really, it's not like he's ever gone somewhere and actually been given a diagnosis.
It's the only thing that makes sense, though.
Because when he does let the names become names in his mind, when he closes his eyes and tastes the name, letting it sit in his mouth, he can see the world completely differently. Jack, instead of being a simple combination of lines, becomes bright, gushing, red-as-blood red. It's the taste of peppermint. It's a million other things that he tends not to think about, because then he's delving too deep into his own mind, and he's never been one for too much introspection.
Others, though.
Jack could spend hours at a time just seeing and tasting other's names. He lets himself do it whenever he meets someone new, when he has a spare moment.
He hasn't had time, yet, for MacGyver.
So.
He closes his eyes (because while he still gets the impression if his eyes are open, he focuses better on the specifics when there's nothing distracting him) and thinks, Angus.
Angus is both a deep, deep red, and a dark green. Angus is grassy hills with sheep all over them. It's the heavy, almost-bitter-but-just-sweet-enough-to-barely-have-a-taste taste of certain kinds of chocolate.
MacGyver. MacGyver is a bright, warm yellow that reminds him of buttermilk. It's bright, so bright and vibrant, blues. It's freshly cut grass. It's the lemony smell of car air fresheners that leave the faintest hint of lemon in your mouth.
Jack opens his eyes and smiles.