While playing arm, I noticed that if you hold a drink, say, a mug, you cant drink from it, I don't understand. I think it would be a good idea to allow ppl to eat and drink from their hands and not from there inventory aka Pockets. I dont see people walking around drinking things from their pockets do you?
I think you might of mistyped a keyword. It -is- possible to drink from items in your hands.
The inventory isn't always in your pockets... Heck... I'd say the stuff in your inventory is rarely in a pocket... It's just about/around your person in an accessible place that you still have an eye on.
Could be on the bar or table in front of you... Blah blah blah. It's acctually considered a bad thing to ALWAYS be holding your drink specially if your sitting at a bar, because most the time your not ALWAYS watching over your drink/having it in your hand. But if you have your big mug and your just wondering around it's understandable but SHRUG.
And as Mansa said, it is possible to drink from your hands.
Creeper
Also, make sure you're typing drink <container>, not drink <liquid>.
So, if you're holding "a wooden cup filled with water", typing 'drink water' won't work, but typing 'drink cup' will.