Looking for a specific "Ohhhhh" reaction from Stewie

I vaguely remember there being a scene where Stewie explains something to Brian only to interrupt himself midway and realize that he could've achieved his goal in a much simpler way. Something like "Oohhh. I probably should've just -"
"Yeah, you probably should've just done [other thing]."

I wanna use that clip for a meme but for the life of me cannot find it, and now I'm wondering if something like it even exists in the show xD Can someone help me out?