Final answer:
The narrator believes the old man groaned due to intense experiences such as physical pain, emotional conflict, or a nearing demise as implied in various literary excerpts provided.
Step-by-step explanation:
Why the narrator believes the old man groaned can be inferred from the context provided in various texts. The groaning often signifies pain or discomfort, possibly due to physical or emotional distress. For instance, in the segment where the character Oldring sinks to his knees after being shot, his groaning could be attributed to the physical agony he experiences from the gunshot wound. The description of his 'limp arm,' 'swaying hulk,' and 'gasp and heave' suggest severe physical distress, leading to a groan.
In another text, referring to an old man sipping blackberry wine, the groan could be symbolic of his existential pain as he lives in an 'indestructible illusion' despite 'the pains and aches of old age.' This groaning reflects his internal struggle rather than a physical one.
In narratives, groaning can also be a device used to create tension or indicate a character's critical state, which prompts the reader to feel empathy or anticipate dramatic events. Therefore, the reason behind an old man's groaning is typically associated with an intense experience, whether physical pain, emotional conflict, or a nearing demise as implied in these literary excerpts.