We know that our resentments (i.e., the built-up or sustained anger which we hold over time), quite literally, have the power to kill us. And, as it is with anger, so too it is with guilt, shame and remorse, etc. If we do not face and deal with the residual feelings of guilt, shame and remorse which we feel for our past and/or current actions, these too have the power to drive the alcoholic addict back to booze and or drugs. Unremedied guilt, like "justified anger," is thus an ego-feeding proposition, a "dubious luxury" that we can no longer afford.
Guilt is essentially an unexpressed fear that our past behaviours will be revealed for all to see, and that named or unnamed "others" will judge us by (and reject us for) such past actions - many of which (at least initially) were taken when we were in the grips of our addiction. Thankfully, in Steps Four through Step Nine we are enabled to face and address past actions that now produce such fears of discovery. And, in Step Ten, we are enabled to proactively face and make amends for any present missteps that could later develop into powerful and dangerous guilt complexes.
By admitting and making amends for our past and current misbehaviour, we rob the ego - that "punishing inner dialogue" which Bill W. so ably describes in the Twelve & Twelve - of much of the raw fuel which it consumes in order to hold sway over us.
In criminal law, the defendant who elects to plead guilty must do so without reservations or explanations, no matter how powerful they may be. There is no such plea of "guilty with an explanation." It is only in the sentencing phase of the trial, after wrongdoing has been established by his or her admission of guilt, that the defendant may address such factors that may (or may not) mitigate or explain the wrong committed.
So, too, in the case of the alcoholic addict an admission of our wrong thinking and wrongdoings must precede the amends we make and the redemption we seek; for it is through the admission of our wrongs in our initial and continuing moral inventories, and in making amends for such wrongs where possible (i.e., when doing so does not harm others), that we address the root cause, rather than the symptoms, of our alcoholic addiction - the acute self-consciousness and ego-centric thinking we had seemingly escaped from by using booze and/or drugs.
Thus, it is by facing and making amends for our wrong actions, rather than by trying to explain away (mostly to ourselves) the guilt and shame we feel in light of such actions, that we are freed from "the wreckage of our past." It is by doing so that we are cut loose from (or, at least, we loosen) the ties of our "old ideas, emotions and attitudes," the mental constructs which seemingly grip us so irrevocably in the throes of our egoic, smaller selves. And, it is by doing so, that we finally awaken to at least the possibility of our emergence into what Bill W. so aptly described as "the sunlight of the Spirit."
If we balk from examining our resentments, fears and conduct, we will inevitably remain in the sway of our own unremedied self, and it will be this smaller self (i.e., the false self of the human ego) that will continue to act as our prosecutor, judge, jury, jailer and (potentially) executor.