WARNING: The following contains spoilers for Dragon Ball Super Chapter 76, by Akira Toriyama, Toyotarou, Caleb Cook and Brandon Bovia, available now in English through Viz Media.
The battle against Granolah keeps getting crazier as Chapter 76 of the Dragon Ball Super manga unveils one of the most shocking plot twists in the series' history: Goku became the voice of reason. The mighty Saiyan has a reputation for not being the sharpest bulb in the crayon box, but if he's being punched or punching is happening nearby, he becomes a prodigious genius. Goku's combat IQ has always been unmatched -- however, his off-battlefield IQ is also unmatched, but in a bad way.
One of the biggest differences between Goku and Vegeta is that when the latter receives a beating, he gets mad, while Goku gets even. Getting stronger would be impossible if Goku never learned from his opponents, so the normally air-headed Saiyan is always watching his opponents' techniques and thinking of ways to counter them. Few characters in the history of Dragon Ball have humiliated Goku on the battlefield to the extent Granolah did. While everyone thought Goku was still gasping, face down in the dirt, he was actually studying his opponent with his only-keen-while-fighting mind.
Granolah's signature technique in Super is a sharp blow to his opponent's vital areas, which he used to send Goku from Ultra Instinct to Ultra Unconscious. When Vegeta's Ultra Ego failed to defeat Granolah as well, Goku re-entered the fray, demonstrating that he'd figured out Granolah's moves. Goku was able to spot the slightest pause in Granolah's movements, allowing him to deduce which vital area his opponent was targeting. In doing so, Goku, while unable to dodge completely, shifts his body just enough that his vital areas are spared from the brunt of Granolah's strike.
This isn't the first time Goku has used Vegeta as a meat shield to study his opponents, either. During the Tournament of Destroyers, Goku was able to outpace Hit's Time Skip technique after watching Vegeta get rag-dolled by the same move. Keeping in mind this was the same tournament in which Goku forfeited and doomed his own planet as a show of honor, it's clear his intelligence begins and ends with battle. He is such an intelligent fighter, it's almost a tragedy his brain becomes a single marble rattling inside a tin can during times of peace.
Goku's intelligence, or borderline offensive lack thereof, has long been a point of contention for Dragon Ball fans. The whole Tournament of Power fiasco aside, he forgets to bring Senzu Beans, forgot the seal for the Evil Containment Wave, and doesn't know what a kiss is -- despite being married with two kids. That particular revelation makes his actions in Dragon Ball Z even more questionable when he volunteered Bulma for Elder Kai to kiss in exchange for helping Gohan. Apparently, he didn't know what he was offering but was just using a word he'd heard somewhere and gathered it was a positive thing.
Goku's true genius in combat makes him a fascinating fighter with compelling battles. However, his general head emptiness in all other walks of life has got to put Dragon Ball in the Top Five all time in terms of audience face-palms per episode. The battle against Granolah has put Goku and Vegeta through a meat grinder that hates Saiyans, but their individual actions have been brilliantly in line with their characters. In Goku's case, that means he has the capacity to be a genius, as long as it doesn't benefit anyone who loves him or his own general life skills.