I never went through detox, so I do not know how long a period you mean, but it took me a few weeks to normalize back to anything resembling my pre-addiction thinking.
I am not talking about reading comprehension or anything like that. I am talking about how I interpreted actions of myself and others and my perception of relationships.
I am not in 12-step recovery, but was in it for many years. It seemed to me to be not a program for the newly clean/sober, for just this reason. I think it works better after someone has passed this early period. I do not know if the idea of "powerlessness" can be understood until you have some time away from drink/drugs and can evaluate behavior before and after. I do not think one has the critical thinking skills needed until things have already started to change.