What is the Tree of the Knowledge of Good and Evil?
The Tree of the Knowledge of Good and Evil is deciding for oneself, independently, what is right or wrong in one’s own eyes.
In the middle of Eden, therefore, the man and the woman face a choice: obey the Lord God and trust and accept that what the Lord God says is good or bad is good or bad, or else decide for themselves what is good or bad. Later in the Bible in the Book of Judges, this will be described as “doing what is right in their own eyes.”
You can see how this choice had to be present in Eden: since God made the man free, the man was free to trust God, or not. The man was free to obey, and free to disobey.
He made his choice.
(And so have we all.)