When you are 10, 5 years is half a lifetime. 10 years is half your life at 20, and 20 years is half your life at 40.
By the time you hit 40, your first 20 years are a distant memory, and you remember choice moments, but you don’t remember those years like when you were younger. The distance in time causes you to lose your ability to hold on to old memories. You can’t hold an ever accumulating amount of memories, and so some fade away. So time stretches the past into a distance too far to see everything.
Meanwhile, 1 year at 10 used to be 1/10 of your life. A year at 20 is 1/20th of your life and a year at 40 is 1/40th of your life. Each year, the lengths of a year as compared to the rest of your life diminishes. So time also shrinks the future while it stretches the past. We live in a time warp, and time goes by faster every day.
Sometimes it’s good to reflect on this, if only just to appreciate the fleeting moments in a day, and know that unless we appreciate the time we have, we can only appreciate the memories that we know will fade away.