Some basis in reality here. We tend to perceive larger chunks of time in terms of a percentage of the time we've been alive. So a 16-year-old's 2-weeks feels about like a 45-year-old's month and a half. Tell a little kid "next year" and you might as well say "give it a decade." By the time you're 80, a year (1/80th of your life) flies by quicker than an anime season when you were a kid. The closer you get to the end, the faster it comes up on you.
Ugh. Feeling old now. Thanks, Mangaka-sensei. 😌