I think you're the first person I've said "there is no such thing as a sugar high" to who actually a) listened and b) was like "you're right" instead of trying to defend its existence. I feel like believing in "sugar highs" is like believing you get different kinds of drunk off different kinds of alcohol. I have friends who swear it is the case. I will tell you what I have done a lot of getting drunk on a lot of different things and it always goes the same for me.
Yeah. The unassailable knowledge of my youth is crumbling around me... Sugar highs aren't real. Turkey doesn't make you sleepy. Pluto isn't a planet. The WOW Signal isn't aliens calling us. Eggs aren't high in cholesterol. And new cars don't have bench seats. I dunno what I know any more!