It is not true that people stop pursuing dreams because they grow old, they grow old because they stop pursuing dreams.
The idea that we will make a society where literally everybody is graded, the good at the top, bad at the bottom, exactly done as it should be, is impossible. There are simply too many random factors: accidents, accidents of birth, accidents of things dropping on people's heads, illnesses, etc. We will never get to grade them, never get to grade people as they should.
悲伤不是线性的过程。它像波浪一样袭来,有时那些波浪会把你击倒。