The last words of Jacob are recorded in chapter 4, complete with an Amen. Then we have another chapter that was added. Remember we are writing on metal plates here. We can't just press delete or backspace so instead we get a denouement.  The encounter with Sherem was important enough that Jacob added it to his record and it is a defining moment for Jacob. We learn more about him. Then, he feels his age and time wearing on him and he describes his life "as it were a dream". Maybe its just me, but I relate to it in a sort of french film noir kind of way. The doomed working-class antihero, alone, haunted by the impending doom of his brothers attacks on his people, resigned to his fate as the defender of Christ and leader of the stiff necked Nephites. As his scene ends he tips his Fedora hat and says, "Adieu".