If Adam and Eve were "perfect" then how could they have made such a simple mistake?

The Bible never says they were created "perfect". It only states they were created without sin.

Lol, I see, let's criticize the Biblical account while disregarding what the Bible actually says. Typical skeptic "logic". Must be the same logic that makes them think using sock puppet votes actually makes them more right.

Free will, same as you and I. Today we also have the choice of 1) go to heaven; or 2)
go to hell.

No one said Adam and Eve were perfect... God is only perfect

The intelligent walking and talking snake was just a bit more perfect and able to share knowledge with them.

Adam and Eve were created perfect meaning without sin. But just because they were doesn't mean they couldn't abuse their free will or freedom of choice. They Chose to Disobey Jehovah God and Chose to rebel against Him and knew Full Well what their Choice would lead to.-Deut 30:19,20

It moved the plot along.

It wasn't a mistake, they had free will to choose having all knowledge, (this includes both good and evil knowledge) or no knowledge at all, and they chose to consume knowledge because they felt it could be useful for them.

God's number 1 angel Satanel offered this knowledge and they decided that it would be good for them, so Adam and Eve accepted it.

It was a perfectly simple mistake.

Who said they were perfect.

Why do you say Adam and Eve were perfect? They were human - with a free will. They chose to disobey. Granted, they only had 1 rule, but whether it is 1 rule or millions of laws, disobedience is still disobedience.

their nature was perfect but their minds were not wise or knowledgeable

Freedom of choice doesn't mean that you'll choose wisely every time.

What do you mean by "perfect" and who says they were perfect? Do you mean physically perfect, morally perfect, intellectually perfect? The word can mean so many different things. Obviously they weren't perfect in every respect, or they would be gods themselves and the fruits of knowledge and the fruits of life would have no effect and they would have been welcome to eat from those trees.
One of the biggest misunderstandings in Genesis 3 is that Adam and Eve were kicked out of the Garden of Eden for disobeying God. They were kicked out to prevent them eating the fruit from the Tree of Life.

True. Toddlers disobey and they are about as innocent as we get. The etiology of evil being a simple mistake makes sense though.

They were innocent and without sin, but not perfect.

Only Jesus was perfect.
No other human has ever been perfect and that is why we all sin, disobey, etc. Because God made us to His likeness but with free will.

They were written to be "perfect," but the story itself was not written to be perfect, since it was written by man.

Because they disobeyed God. They may had been made perfect but obviously Eve was susceptible to Satan's temptation.