I have the perfect answer for you.
As we become older, starting with say a 1 year old:
A week is 1.92% of your life so far. So a week is a significant portion of time.
For say, a 60 year old: a week is 0.032% of life so far.
Time is a matter of perspective. As we grow older we perceive it differently; which causes the feeling of increasing speed.
Of course, other external factors such as lifestyle and responsibilities can also have an effect on this.