The Symmetry Argument I

Now that the idyllic lazy days of summer draw to a close, and we again face the pangs of last remembrance, I draw my pen towards contemplating what I find to be one of the most beautiful philosophical arguments I have encountered. I find this argument immensely satisfying because of its simplicity, elegance, and durability under the duress of philosophical inquiry. But furthermore, it counters our intuition about death yet is incredibly difficult to argue against. Lastly, it was first described by a Greek philosopher who was not Socrates, Plato, or Aristotle. I tend to be convinced by this argument. I'll present it today and discuss it tomorrow.

This is from De rerum natura by the Epicurean poet Lucretius who argues that we should not fear death.
1. I do not regret or fear not being born earlier. That is, I don't lament the fact that I was born in 1984 rather than 1980.
2. By symmetry, I should not regret or fear dying earlier. I should not regret or fear dying in 2020 rather than 2024.
It hinges on a claim that our past nonexistence is equally unimportant as our future nonexistence, and hence, if we do not fear or regret our past nonexistence, we should not fear or regret our future nonexistence (that is, death).