I'm pretty sure we understand, and you're also under the false impression that sleeping the monster un-enrages them. Sleep does no such thing.

Rage can be thought of as a status effect. Every attack does enrage damage and claw actions in particular apply a very high percentage-based amount. Once enraged, the monster is locked into that state for a set amount of time. This timer drains even through area changes and periods when the monster is asleep, but there is no way to knock monsters out of it with the exception of inducing a stagger on Rajang's tail twice -- or at least I think it's twice. This can all be seen when using HelloWorld's overlay mod which exposes this data to us.

What is exceptional is that, for the purpose of flinch shots, the brief period while the monster is performing their wake-up animation doesn't technically count as an enraged state, despite the timer continuing to tick if they were enraged prior to being slept and subsequently woken up.