Looking at old pictures helps, I think. If settings are a current difficulty, then looking at the settings helps somewhat.
But the relationship between the settings, subject, composition and light is what makes or breaks a picture. To me, there are probably better ways to learn settings: an external light meter and manual mode, for example, will provide a tactile path of experiencing the relationships.
To me, the big benefits of looking at my old pictures is to remember what I am capable of making and to understand what and how I see.
The important part is “Why did I make this picture and why did I make it like that?”
The problem with old pictures as a source of technical information is that I used to spend a lot of effort saving pictures with technical weaknesses. It is easy to crop a poorly framed picture. Easy to brighten for under exposure. Easy to sharpen away slightly off focus. Etc. Etc.