Few things have the potential to cause more anxiety in moms and dads than milestones. Somehow, our children are expected to grow and learn according to a schedule, and we start to worry when our kids don't adhere to that schedule. "Comparison is the thief of joy," recites Dr. Andrew Irwin, a pediatrician from Tennessee. "When a mother comes into our office asking about her kid and compares him or her to a sibling or neighbor, the biggest advice we can offer is to stop comparing. When we stop seeing gradual progress is when concerns may arise, but each child is different and may not follow the same path." Read on to see what Dr. Irwin shared with us regarding the most commonly asked questions about milestones.