this is the original sin, choosing my will over G-d's will.
matthew henry commentary: "“Behold, the man has become as one of us, to know good and evil! A goodly god he makes! Does he not? See what he has got, what preferments, what advantages, by eating forbidden fruit!” This was said to awaken and humble them, and to bring them to a sense of their sin and folly, and to repentance for it, that, seeing themselves thus wretchedly deceived by following the devil's counsel, they might henceforth pursue the happiness God should offer in the way he should prescribe."
looking at it like this, G-d has a sense of humor!

check out the rest of this commentary here:
http://chatbible.com/genesis/3-22.asp