-Noach was busy trying to rectify the sin of Adom.
-By drinking wine one can reach a state of conciseness needed to start rectifying Malchus (the sefirah of kingship)
-Meaning there are certain states of conciseness that can be self induced through meditation, other states need outside stimulants.
-One would have to understand the exact mahus (properties, characteristics) of the wine and what it represents. When meditating on this he can achieve the above state of conciseness.