The questions "how do AC upgrade priorities work?" and "is there an afterlife?" have incredible similarities:

1. There is no shortage of people who claim to know exactly how it works.
2. Nobody, in fact, really knows.
3. There is no way you *can* know (hell, AC doesn't even know how it works).
4. You can choose to live life in fear and frustration because of not knowing, or you can just resign yourself: it's unknowable and you should really worry about things you can control so that you can be happy.