going back in time
When you travel back in time in a dream consider the possibility that this represents an aspect of your personality/psyche that is in a state of regression. This could be a state of regression defined against the collective (e.g. like dreaming of living in the Victorian age, or being fascinated by Victorian culture) or a regression as defined by one's own psyche (e.g. a father or mother complex). The TV show Lost, in most episodes, suggests via frequent flashbacks that the featured character's experience in the present is psychologically determined by a conflict from the past. These flashbacks indicate that the character is in a regressive state of some kind with respect to his or her present circumstance. Sometimes the episode shows a character who renews his or her ties to that past conflict and the complex is intensified, sometimes the character experiences a release from the past conflict and the complex is thereby depotentiated.