Green’s Dictionary of Slang

(US campus/teen) wanting to know what is going on, to be aware of the facts, being nosy or inquisitive; thus all up in the koolaid without knowing the flavor, ignorant, unaware.

1997–2000		Da Bomb 🌐 all up in da koolaid and don’t kno da flava! (phr) When someone is intrusive about something that is none of their business and about which they know nothing. Stay outta this man, u all up in da koolaid and don’t even kno da flava!
2001		Bebe Moore What You Owe Me 206: Mom, why you all up in the Kool-Aid? Your beautiful sister happens to be more generous than you are.
2002		J. Sayers posting 22 Feb. 🌐 i think you over-reacted and took things too personally, because while she insulted you, you didn’t know the bullshit she had to go through and the pain she was feeling. indeed, you were all up in the koolaid without knowing the flavor.
2002		D. Zamora From Victim to Princess 86: She is all up in the Kool Aide, but not even knowing the flavor. Ms. Complainer is usually the first one up on Ma Bell’s phone lines yapping to everyone.
2007		J.A. Henderson Bunker 10 176: These posers gonna be sorry for gettin’ all up in the Kool-Aid.