Time is an idea humans set forth to organize daily life. Even though it is just an idea, major parts of life revolve around it. How do people perceive time? Remember as a child how far holidays seemed to be. Now, growing up, they seem to fly by. There must be a reason for this. As people age, their perception of time changes.
As a person ages they experience more time. Basing from time that someone has observed before acts as a ‘boost’, speeding up time you feel in the present. Children have experienced less time than adults, thus making it seem like time goes longer because children have less to base off of. Adults, however, have experienced time much more, and being able to base it off more, making it seem to go fast.
Mathematically, P=1/A where P is the perception of time, 1 is one year, and A is age in years. For example, a five year old is perceiving one-fifth of of the total time he has experienced. A forty year old, however, is perceiving one-fortieth of his total time. The difference between these two amounts is staggering; one-fortieth of a life is much less than one-fifth of a life.
To summarize, as you experience more time you have something to base the present off of, making it seem to flow faster. On the other hand, being younger makes it seem slower. To put simply, time is perceived in direct ratio with age. As someone grows older, their perception of time passing increases.