Codependence is all about external validation. It's taking our cues from others about how we should be feeling or are allowed to feel or "made" to feel.
For me, this was learned in a home that had no alcohol problems, but plenty of emotional hiding. I was adopted and my story was told to me, but my real experience was not in the least okay for me to have. I always longed to know who I really was, but my true identity was never for me to have. So that was crazy making and I learned from minute one that my life and my feelings were not my own. My adoptive mother struggled with anger and fear. I'm sure that her four kids brought out many feelings of her own painful childhood, which she never reconciled. In our house, it was all about good behavior and when you crossed the line, the paddle came out. I learned early and often that my real feelings were dangerous, so it was safer to feel what I was told to feel. Of course, humans don't work that way. Took me 55 years to realize that the dance I'd always fallen into with romantic partners was codependence. It was an elusive realization for so long because I always thought that codependence was something children learned only in alcoholic families.