I was attending a technical conference yesterday in which one of the speakers was talking about the human brain. He pointed out that the only actual physical result of brain activity is muscle movement.
Lots of activity goes on within our brain itself, he noted. But when all is said and done, none of that cogitation is transmitted out into the world, except through the action of our body’s muscles.
When I heard this, I turned to the person sitting next to me and said “Just thinking about that makes me break out in a sweat.”