Progress, from: To Outlive Eterninty and Other Stories (Baen 2007)
(Originally appeared in The Magazine of Fantasy and Science Fiction, January 1962)

I just read this story and liked it, but.... I don't know that I understood the last line of the story.

I won't give any details in this first post, to avoid spoiling it for those who have not read it.

If anyone has read this story, can you tell me what that last line meant? The way it is presented suggests to me that it is meant to be significant, and so probably not something that was mentioned at the start of the conversation in which it appears.

The only other interpretation that occurs to me seems to be contradicted by something earlier in the story...so I am at a loss.

I really like Anderson's stories and ideas, and am concerned I might be missing something here.

Thanks for any help.