Considering he pointed out that using the Object-replacement device Dib would no longer be Zim's enemy, the chaotic robot is definitely smart enough to grasp temporal causality
I'm suprised they didn't have the moment when he crosses the data (I mean taco) beam, and his brain gets transfused with the base computer, but for a few awesome seconds, he's just flying around the room getting electrocuted, screaming, "Wheeeeeeeeeeeehoooooooooo!!!!!!!"
3:22 Gir: It was me! I was the turkey all along! Zim: I was wondering what that turkey was doing there. Gir! I'm delaying the brain parasite plan for now. I want you to... Gir: I WAS THE TURKEY!!! MEEE!!! Me: *falling out of my chair laughing*
Gir really is great ADHD representation. We see that he actually attempts to serve Zim but immediately loses focus and forgets what he's doing if the task at hand isn't stimulating enough. Also he has a hard time following and visualizing descriptions or explanations and often pretends like he's following along, despite having lost focus early on in the conversation.
He's so adorable ouo I wish I was allowed to watch this show back when this show was on, but Mom didn't think I should watch it at that age, (I was like seven)
Gir: G.I.R. Reporting for duty! Zim: G.I.R.? What does the G stand for? Gir: I don’t know. “Silence for a few seconds” Gir: “wheezing and whooping” Zim: umm, is it supposed to be stupid? “Gir is still wheezing and whooping” Random thing: it’s not stupid, it’s advaaaaanced.