Yeah, Benadryl is a weird drug. Look at its interactions with various receptor sites in humans: https://en.wikipedia.org/wiki/Diphenhydramine#Pharmacology

Benadryl does nothing to me except kill my deep and REM sleep and leave me "sleeping" but conscious. I'm exhausted the next day. I only take cetrizine.

agreed, any drowsy things seem to turn off weird parts of my brain but im left feeling like an awake zombie