Why Grandparents are Older

My granddaughter age 5 was sitting in my lap as we were reading a book together.   "What are those?"  She asks with curiosity and partial disgust pointing to the large veins on the back of my hands.  "Oh," I replied.  "Those are veins that carry blood back to my heart."  She raised her eyebrows, shrugged her shoulders and went back to reading.  Old grandparents provide lots of experience for young grandchildren.