Is repentance obligatory for sins—major and minor—even without knowledge of being held accountable for them?

As for one who commits a sin out of ignorance, the issue of his sinfulness has been elaborated in Fatwa no. 123365. However, one who knows that he has committed a major sin must repent from it immediately. And whoever commits a sin then forgets it, general repentance that encompasses all sins is sufficient for him, as stated in Fatwas no. 113105 and 123510.