Why 'stupid'? If it is something you do not know, it must be lack of experience, right?
I know a bride was supposed to be 'innocent', that is, a virgin and totally lacking in sexual knowledge, which means the wedding night must have been a profound shock. That is stupid.
I agree that 'innocence' as in purposely keeping others from knowledge is also stupid, if not oppressive, as it makes them less able to cope, or indeed manage their own lives.