Edit: what was different about how you perceived time?
I equate this to each year being a smaller period of your overall time. When you turned 5 a year was 20% of your life, at 50 it is 2%. Perceptually that is huge.
for me personally its mostly about routine i think. time just looses its meaning while doing the daily grind.
but honestly, the article spoke about it better then i ever could :)
When you're a kid, you change schools, pass exams which serve as time markers, have various important lifetime events. As a young adult, there are a bunch of those too.
You know you're getting old when you start measuring your life by events related to your children or grandchildren.
Older people have fewer of those, especially ones in a stable situation.