Past Simple and Present Perfect

Solution 1:

I think that your question can be answered keeping in mind the difference between "Definite Past" (when we use the Simple Past Tense) or "Indefinite Past" (when we use the Present Perfect Tense).

If we have in a sentence words or expressions that define the moment of the time when the action occurred (for example, yesterday), we work with the Simple Past Tense. On the other hand, if the sentence lacks words or expressions that determine the time of the action in the past, we use the Present Perfect Tense.

We must remember that the Present Perfect can also be used to express an action that started in the past and continues in the present. In this case, the words "since" and "for", among others, can be used. In my opinion, "back then, at that time, when I was young" are expressions that express a kind of past that is defined. So, we should use the "Simple Past".