Changing others is a futile goal? You can’t change others. You can encourage behaviors, but you can’t force anyone into anything. You can however change yourself – to a certain extent, but I’m not going to get into the genetics of personality here.
You’re doing your best; examining your behaviors, checking yourself, putting in safeguards, but then you buy something you didn’t mean to. Maybe you slipped emotionally, or fiscally. Whatever it happens.