Grandparents have always been important. Today, they're even more important. In busy, two-career and single-parent families, an involved grandparent goes a long way to filling a void for children. In extreme situations, the courts have found it's often a grandparent who can reach a troubled teen when no one else can.
Some people, genetically, are born with weaker or smaller veins than others - and some people are born with larger, and more flexible vein tissues. Due to genetics, some people just have poor, weak veins. This only affects the large return veins you can see however - the veins which transport the rest of your blood are likely fine. Regardless of the vein size, blood can still be drawn. I personally have smaller and weaker veins, and can still donate, but sometimes it takes a few tries.
Why are valves more important in arm veins and leg veins than in neck veins? Valves are more important in arm veins and leg veins than in neck veins because, when you are standing, gravity causes pooling of blood in the veins of the free limbs but aids the flow of blood in neck veins back toward the heart. A person who has liver failure cannot synthesize the normal amount of plasma proteins.