Hi Pinot.
I think that simply writing a list of regrets that are holdovers from our drinking days can be painful...a form of self-torture.
The AA Big Book Twelve Steps provide for this. Along the way while we're working with our sponsors, we make a list of resentments (past and present) and other regrets, and our motivations that precipitated our resentments. We then go over these things with our sponsors, sometimes with our therapists instead, and ideally gain some insight as to why the things we did, or that were done to us, affected us in the ways they did. (The Big Book talks about sharing this information with someone we trust, such as a priest, but the book was written at a time when there were precious few people who qualified for sponsorship.)
Ideally, and for many people, me included, this process results in our resentments and regrets losing their power and intensity. We're than freer to and more capable of moving forward and living our lives. This is the work of the Fourth and Fifth Steps, the first three Steps being conclusions of the mind rather than what we traditionally refer to as "work." Some people repeat this process down the line, a kind of sober cleansing, if and when one feels the need to do so.
The important element here is that we don't secretly hold onto these things; rather, we share them with someone we trust, someone who knows us well, and someone who will not judge us for what we've done or what we feel. It's been my experience that this process also works well in therapy.
Edit: Just wanted to add that making such a list alone is about what we were and what we now are, but it doesn't include what we can become, an important aspect of recovery. And that's why it's important to share it with someone else, usually a sponsor.