It's an odd sensation, the feeling that this experience with a favorite artist might just be it. That the book you are savoring or the story you are reading may well be the final one she or he will write. That this tour will probably be your last chance to see a beloved band.

That sense was part of what drew this Rolling Stones fan, and no doubt countless others, to a recent concert. Now, a self-proclaimed goodbye tour is a time-tested audience-enhancer for flagging bands, but that doesn't describe the Stones. They aren't talking about calling it a day — not openly, at least. Their last real album, "A Bigger Bang," was their best in years. Their recent performances have gotten deservedly strong reviews.

But the-end-is-near fear hangs palpably over the band's 50th anniversary expedition. It's not that Mick and Keith, both 69, are old. Not by today's standards. Nor is Charlie Watts, at 72. Rather, it's that they are pressing hard against our expectations for rock musicians. You can't be skipping around the stage singing "Sympathy for the Devil" at 75, at 80 … can you?

The same sensation comes in reading "Dear Life," the latest collection of short stories by Alice Munro, a literary nonpareil whose subtle, penetrating tales can leave you thinking for days. A sense of summing up is there not only in the stories themselves, but in the note that precedes the last four, about a girl growing up just beyond the borders of an Ontario farm town, with a stern father and a mother who hopes for more than provincial life offers.

"I believe they are the first and last — and the closest — things I have to say about my own life," she writes.

It's also there in her answer, in a November 2012 interview with the New Yorker, to a query about her periodic assertions that she is all done writing. "I do stop — for some strange notion of being 'more normal,' taking things easy," Munro said. "Then some poking idea comes. This time, I think it's for real. I'm 81, losing names or words in a commonplace way, so …"

Then there's Kris Kristofferson, who turns 77 today, declaring in "Feeling Mortal," the title track of his latest album: "God almighty here I am/Am I where I ought to be/I've begun to soon descend/like the sun into the sea."

And Donald Hall, former U.S. poet laureate, who recently told the Boston Globe that though he used to rise at 5 a.m. and work for 10 hours a day, the most he can put in now, at 84, is an hour or two. "Energy diminishes — obviously — as you get older, pretty continuously," he said, an observation that calls to mind Stephen Spender's lament that "What I had not foreseen/Was the gradual day/Weakening the will/Leaking the brightness away."

But why does that cause angst for us appreciators who are years younger?

In part, it's the impending end of a musical or literary experience whose regular recurrence has become a pleasurable part of your life. That's why this reader felt bereaved back in 1995 when Robertson Davies, whose literary output had been undiminished by age, died of a stroke at 82. It also explains the rush of gladness one feels at the publication of a new story by William Trevor, whose output in his mid-80s has been slowed by illness.

Something beyond that is also at play, however, as you yourself get older: The uncomfortable recognition that an era that has defined your early and middle adulthood is coming to a close. It's a sense of lengthening shadows, a vicarious midlife shiver.

That's one reason I selfishly hope that ideas keep poking Munro. That Kristofferson starts feeling a little less mortal. That Trevor's trove isn't yet complete. That Hall keeps spending that hour or two writing.

And that Mick and Keith and Charlie and Ronnie decide that, yes, you can still get them rocking at 75, or maybe even 80 — so that this doesn't have to be the last time after all.