"The suggestion was sensible; and yet I could not force myself to act on it."
~Jane Eyre by Charlotte Bronte, page 470
I think Jane had to go back to Thornfield in the end. She needed the closure--as did the reader. Though I half expected her to marry Rochester in the end, I did have my doubts. I think, though, that that was the only way to end it--the only way that wouldn't be overly bittersweet, at least. Jane couldn't marry St. John. It would have been a loveless marriage. Neither would have been truly happy. Jane would not have been fully happy living on her own, even though she was fully prepared to do that. Only by marrying her one true love could she be happy.