Much of the literature which recreates the myth focuses attention on the point when Orpheus turns to look at Eurydice on their journey back to the land of the living. It is most often described as a mistake or failure, or as the result of an overwhelming compulsion, a rush of longing which leads to the fatal error.
This suggests that the myth is about human frailty, that the really satisfactory outcome would have been the reinstatement of Eurydice in the land of the living.
Yet the words mistake and failure sit oddly in the context of a myth which asserts the incontrovertible fact that death is immutable. If, however, one reads the myth as if it were a dream in which different emotions and thoughts can be made manifest with a simultaneity which is not possible to the conscious mind, an alternative interpretation becomes available.
We must all be familiar with the fantasy of reconstructing the past with a different outcome. This is a vehicle for expressing regret, responsibility for some disaster, (whether it was actually within ones control or not) and loss. It also provides temporary relief from consciousness of the reality of trauma. Orpheus' journey to the Underworld, his use of his great talent ( his intrinsic identity) to overcome the normal boundaries for humans is a fantasy of this kind.
It is however essential to survival and to recovery from trauma that such fantasies do not persist, but that there is a ' therapeutic return to reality'. The looking back by Orpheus is then the pivotal point of the myth where he makes this jump from fantasy to recognition of reality, and he experiences it with all the intensity of the original event. This again is familiar to us: the return to reality is made unwillingly by the conscious mind and is experienced as shock.
It is essential to the success of the change of consciousness that the process is concealed from the subject, otherwise one would, and does, resist it powerfully. The mechanism therefore appears in disguise as the condition which Hades imposes and Orpheus flouts.
Thus, in the midst of his determination to rescue Eurydice,one might say that ' in another part of his mind', he knows he cannot undo the past and overcome death. The overwhelming compulsion that he feels is the reinstatement of reality to his consciousness.
I think one of the reasons why the myth has retained its power over time is that hi has so much to reach us about grief and survival of loss. We learn that fantasy plays an essential part in the assimilation of loss and that a return to reality is necessary to recovery.