Here is my oldest/youngest WDW visitor story, I have this on my profile on the "Meet the Team" section here on this site.
We were staying at the Poly, me, my husband, my then 3 year old and 7-month old. Every morning while my husband and kids were still sleeping, I would go for a walk around the lovely grounds. And each morning I would see this very old lady sitting on her balcony drinking tea. She must have been close to 100 years old. I would study her face as I jogged by and wondered what her life must have been like, the fact that she was at WDW was facinating to me. I made a mental note to paint her portrait when I got home, as she made such an impression on me. We would always exchange hellos, but that was about it. Then on our last night at WDW, we went to the beach at the Poly to watch the fireworks. I looked over and saw this lovely old woman sitting in a chair with her family. Of course this was my opportunity to go speak with her. It turned out she was 97 years old and had been coming to WDW every other year with her family for the past 20 years. She owned just about every Disney movie ever made, and was a huge fan. She was just so very kind, and so very interesting. My baby started crying and fussing, and she asked if she could hold him. She eventually rocked him to sleep. I took a picture of them, I was so touched, and when I returned home I painted her portrait holding my son. It actually hangs in our living room and reminds me of the Circle of Life.
(sorry so long, but I thought it an appropriate time to share this story of the old and young in WDW!)