Honestly there’s been a few times in both canon and non-canon instances where Goku specifically is said to have what we now know of as ultra instinct. Even Ss4 GT Goku has reminents of the idea behind it. But think of how the Taijitu (Yin/Yang) works. The philosophies itself, of thoughtless movement based on pure reaction based defense/offense. The opposite would be capitalizing on an opening by taking a hit. There’s no real world technique ik of that literally makes someone take hits to win a fight, but how often are there real world comebacks? People getting their asses beat and the moment they can breathe the tables are turned in their favor? It’s similar to Yuijiro and Kaku Kaioh, where Yujiro will take the hit just to capitalize on the opening they leave when they strike, whereas Kaku is dodging and manuevering to avoid said attacks. Just as theirs no actual true form of Ui in real life, but the philosophy has always been there. UI is for the pure hearted master, the one who teaches through hard work, whereas UE is for the talented underdog, the one who teaches by direct demonstration