Perhaps, but I can experience things unmodified humans cannot. Diving into the deepest trenches of the ocean, short unarmored void-walks in space, that sort of thing. I am blessed by a direct genetic lineage from the God of the Imperium, sacrificing the dubious blessing of drunken forgetfulness seems a small thing.

[ He pauses, shifting his head in something like a smile. ]

Besides, I am told that the Space Wolves chapter of Space marines produces Mjod, which can produce something like drunkeness even in our metabolism.