The Tree of Knowledge of Good and Evil

I'm currently reading a book on the Bible by Peter Kreeft. I'm only a couple of chapters into it but it is good. It goes book by book through the Bible and touches on the basics. I think it's important to always go back to the basics. Anyway, the quote I'm going to post, from the book, is talking about this following passage...

But of the tree of knowledge of good and evil, thou shalt not eat. For in what day soever thou shalt eat of it, thou shalt die the death. (Gen 2:17)

And from the book...

By the way, the word knowledge here means "experience". God wanted to keep us from the knowledge of good-and-evil that comes from experiencing and tasting it (thus the image of eating fruit), not from the knowledge that understands it. The same word is used in Genesis 4 for sexual intercourse: Adam "knew" Eve,and the result was not a book but a baby.(Peter Kreeft)

I always read the word knowledge in verse 17 as a mental understanding. I also got a chuckle out of how Kreeft explains it.