How submerged does a reference have to be before it drowns?

“Young, middle-aged, elderly, old, dead: this was how life conjugated. (No, life…”

“What does the novel do? It tells beautiful, shapely lies which enclose hard, ex…”

“Yes, of course we were pretentious -- what else is youth for?”

“We thought we were being mature when we were only being safe. We imagined we we…”