Locked Out

This is a phrase used to describe somebody who is lost, inattentive, or just generally confused. Somebody who does not understand the task presented before them.

This is a reversal of the more common phrase "Locked In"

Roman: Yo can you, like, share the unit 2 precalc notes ?
Nate: What notes?
Roman: Like, the one literally due next period, before our quiz?
Nate: We have a quiz today?!
Roman: You're so locked out.