Why is it that time seems to pass faster the older we get? Well, there is a mathematical explanation. When taught fractions, students are often shown a "pie" with equal size wedges to represent the fractions. Picture such a pie with 4 wedges. This represents a 4 year old. Now imagine traveling around the edge of the pie at a constant rate of speed. Now, imagine traveling, at that same rate of speed,  around the edge of a pie that has 40 wedges instead of only 4. How much more quickly will you traverse one of the wedges?