The Lord God said, "The man has become like one of us. He can now tell the difference between good and evil. He must not be allowed to reach out his hand and pick fruit from the tree of life and eat it. If he does, he will live forever."
This verse reminds me of a story my sister recently told me about her van full of kids, all playing a rhyming game. Then they started to make up words that rhymed with 'truck'. Which ultimately lead to one of the darlings repeatedly yelling her submission. A word which happens to be considered in polite societies one of the naughtiest of utterances (though she had innocent intentions.)
She had not known. The sounds she made were only to try to keep with the rules of the game. She was happy. Then one of the worldlier children explained to her she must not use the word because it has negative associations. She discovered her word, while it did rhyme, was certainly not one she should be yelling (particularly right in front of her mother).
I don't think using cuss words is a sin. Possibly rude, possibly ineffectual, at times deeply satisfying, but not a sin. Using them to curse people surely is. My point is just that, like my niece, we discovered our sin in the garden that day. We gained some knowledge, some contextual understanding... and look where it got us.
Not happier certainly.
Should we cling to the possibility that ignorance is bliss?
No. We can't afford to. But should we be prepared for what knowledge brings here on this side of the curse? Yes. You must take care with what your mind consumes. As it says in Spiderman. With great power comes great responsibility. So to with knowledge and understanding.