Lol. Maybe this is why he was given a wife. Brilliant, even better.
Notice, in that newly discovered ancient manuscript, immortalized on page 6 of this thread, that documents a discussion between Adam and God, that I definitely did not make up, you can get a sense of how futile it would be to attempt to steer a man that can't tell good from evil.
A man that has no knowledge of good and evil can't be given a reason "why" he should refrain, other than a direct threat to his own physical experience, just a general consequence in a cause/effect relationship.
Perhaps the "tree" lie was just another "white lie" told by God because there was no other way to explain it Adam. "You'll die if you eat from that tree" might have been the only way to get Adam to respond, much like "You'll go blind if you keep jerking it around the garden."
So he understood that God gave him instructions, and he followed them. He knew God was in charge. Adam understood he was subservient to God.
Adam was mentally capable...
He could understand facts told to him. And logic. But since he didn't understand good from evil, right from wrong, navigating a world of free will would be like navigating a world of color when all you can see is gray.