NPCs refering to our character's age

[DPZ2]

^ We don't really know the life expectancy of the average Eorzean, though. In the real world, most people up until the 20th century could only expect to live to about 35 or so...

Let's be clear here. Life expectancy is based on the sum total of ages at death divided by the number of the dying.

If you lived to 35, you were as likely to reach 70 as anyone today, as most of the deaths figuring into that sum total were under 1 year of age.

To be clear, life was harsher, and there were more opportunities for accidental death, but "you live to 35 and then, poof, you're gone" wasn't a real thing.