hehe good question may i say?!
I think it is there to instruct the body for its actions!
The mind is a little man who can see through our eyes, sense and feel through our feelings :)
He decides If we are having a coffee, then he tells us/orders us to move our body and like a robot make a coffee, then he makes us pour it down our necks so he gan get a fix :)
That's the only way I can answer it , or might come back to this.