Making the most of every moment together is a lesson the remarkable young man you'll meet on Sunday knows all too well. He's a little boy in a big hurry... because he's fighting a disease that makes him age too fast. He's smart, he's funny, and he's got a lesson for us all.

Dateline Correspondent Rob Stafford introduces us to the remarkable Seth Cook.

"As I drove the long winding road into the small logging town of Darrington, Washington, I worried about the little boy I was about to profile. Seth Cook has progeria, a rare premature-aging disease that is terminal. I thought about my own kids and how I would react to such a dire diagnosis. And I was concerned that if Seth sensed any apprehension on my part, I would hurt his feelings and that was the last thing I wanted to do.

Then I met Seth and he was not the boy I expected. Yes, like all children with progeria, he is frail and tiny. Seth stands just three feet tall and weighs only 25 pounds —the size of an average 2 or 3-year-old. But as soon as he spoke, I was struck by his confidence, strength and above all his optimism. Right away, he put me at ease — and I'm supposed to be the one making him feel comfortable. Soon Seth was showing me around town where it's clear he's the smallest big man on campus. Everyone knows Seth." Click here to read more of Rob's blog.

Click here to learn more about progeria and Seth's story in advance of the broadcast -- including a special slideshow.

Image: Dan Delong | Seattle Post-Intelligencer

Join us Sunday night at 7 p.m./ 6 Central for Dateline NBC.