It is no secret that compared to most of the other characters in Dragon Ball, Goku is a bit of an airhead–not to say he’s stupid, just that he is a bit naive about certain aspects of everyday life that come naturally to seemingly most people, with absolutely no desire to educate himself. However, when Goku and the Z-Fighters were facing off against the greatest threat Earth had seen up until that point, Dragon Ball introduced a fighter who makes Goku look like a genius.
Upon taking a look at Goku's origin, it is easy to see why he has little understanding (and even less interest) in everyday human life. Even before his Grandpa Gohan died, Goku was raised practically in isolation, so developmentally speaking, Goku was a bit behind–and that’s not even considering his head injury. Apparently, Goku was initially aggressive and inherently bloodthirsty when he was a baby just like every other Saiyan, but after he fell into a crevasse and hit his head, he became the sweet and hopeful Goku fans know and love today. Unfortunately, it seems like that injury did more than just give Goku a more agreeable and less murder-y personality as it seemingly also played a role in his perceived intellectual shortcomings. However, even with potential brain damage, Goku is at least smarter than one fighter, who is either really stupid or dangerously delusional.
In Dragon Ball chapter 396 by Akira Toriyama, the Cell Games have begun, and the world’s greatest fighters answered the call–and then Mr. Satan showed up. Mr. Satan is Dragon Ball’s answer to professional wrestlers from such agencies as WWE or RAW, meaning that he’s still very strong, is an impressive fighter when compared to other normal humans (those without the ability to manifest their ki into energy blasts), and most importantly, he’s flashy. When Mr. Satan showed up to the Cell Games, he was followed by news cameras that were live-streaming the whole thing and Mr. Satan gave them a show by loudly claiming that he’s the best fighter in the world, demonstrating his strength by breaking 14 out of 15 stacked roof tiles with a single chop, and showing off his championship belt. Then, the fight with Perfect Cell begins.
Mr. Satan is Either Dragon Ball’s Dumbest Fighter, or its Most Delusional
As one would expect, Cell knocks Mr. Satan out of the ring with a single, unenthusiastic hit–one which sends him flying into a nearby mountain. When Mr. Satan is asked about this, he says that he just slipped, and that he’s ready to fight Cell again if given the chance. This Dragon Ball chapter proves that Mr. Satan is unquestionably a moron. Even if he knew that he couldn’t beat Cell and wasn’t just wrapped up in his own delusion, the fact that he’d step into the ring with someone who just wiped out entire cities filled with people and who threatened to destroy the planet in a tournament where killing is allowed is irredeemably stupidity. Even if Mr. Satan had to go to keep up his image, that is still no excuse to put his life on the line.
Mr. Satan’s actions show that, similar to Goku, he doesn’t have much common sense, though unlike Goku, he can’t make up for that lack of intelligence with genius-level fighting ability and martial arts understanding–not to mention the god-tier power Goku was wielding practically from the start. So, while Goku isn’t the brightest of the bunch and constantly gets under Vegeta’s skin because of it, he is more than proficient in at least one aspect of his professional life (fighting) whereas Mr. Satan is just lucky Cell didn’t kill him as soon as he laid eyes on him–proving that Mr. Satan is the one Dragon Ball fighter who makes Goku look like a genius.