The border dweller Brown has an interesting response when Roland asks if he believes in an afterlife: "I think this is it."
Roland's question came about following his observation of Brown's eating habits, notably the blessings the dweller offered to rain, health, and expansion of spirit. It seems that Roland was surprised at the prospect of Brown being, at least on some level, a man of faith.
It seems obvious (considering that I've read the entire series more times than is probably healthy for anyone) that Roland was aware of Brown's connection to the Manni. Brown admitted to living with the Manni for a time but deciding it was "no life for me" since the group was always "looking for holes in the world."
Holes in the world ... definitely something Roland was well aware of. Taking this into consideration, it made me wonder how Roland felt about Brown's view of his current reality as some sort of an afterlife.