Today is my 29th birthday. One more year until Carousel.

In my late teens, I would tell people that my life would end at age 30, and they would assume that I planned to kill myself, when in fact I was just enamoured with the idea of ceasing to exist at 30, believing that a deadline, even an imaginary one, would push me to accomplish more in my 20s.

So much for that.

Andrew Niccol's In Time is set in a future in which humans who reach age 25 are given one more year to live unless they can earn additional time.

The film focuses on the immortality aspect of its conceit, but I am more interested in the people who would not extend. What if a miserable person could opt out of life without shame? What if a 25-year-old was satisfied with the life that he or she had lived?

In Logan's Run the novel, everyone is killed on their 21st birthday.

At least you'd never have to write a cover letter.