Rituals *can* mean habit. It's hard to tell from this small bit of text what is going on exactly. It could be a ritual in the full sense, of some kind of large-scale activity designed to ask for help from the Gods or something like that. However, either way, I can answer about "don't care". I don't think they are literally attributing feelings or "care" to the ritual. Rather, they are saying the ritual will work or not---it will do or not to whatever it does---without any regard to whether the person has quit drinking (alcohol). In this text, it's clearly understood that this person means he quit drinking alcohol.