I can't believe it either. I was 13 years old in the year 2001. 3 more years and it'll be 20 years since 2001. You're right time does fly.
When I was 13 the year 2017 seemed so far away. But now that I'm here in the year 2017 it only seems like maybe 5 years have passed. But not 16 almost 17 years.
On another note. It's already been 2 and half years since I moved to my new place and it only seems like one year ago. I'll be here at my new house for 3 years as of December 1st 2017.
Time sure does fly.