How to comprehend "age"?
The sentence is quoted form Bill Gates 2007 Harvard Commencement Speech, the original words are " In line with the promise of this age, I want to exhort each of the graduates here to take on an issue - a complex problem, a deep inequity, and become a specialist on it."

In my opinion, I would assume that the "age" is Bill Gates' physiological age, the "promise" is Bill Gates' promise. But another comprehension exsit also, in this way it means the time of society, the promise of society. I want to know which one is right ?
I hope someone of kind heart will give me a proper explanation.
Sincerely~

Question

How to comprehend "age"?
The sentence is quoted form Bill Gates 2007 Harvard Commencement Speech, the original words are " In line with the promise of this age, I want to exhort each of the graduates here to take on an issue - a complex problem, a deep inequity, and become a specialist on it."

In my opinion, I would assume that the "age" is Bill Gates' physiological age, the "promise" is Bill Gates' promise. But another comprehension exsit also, in this way it means the time of society, the promise of society.  I want to know which one is right ?
I hope someone of kind heart will give me a proper explanation.
Sincerely~

Answer

Your second interpretation is more correct.  Bill Gates is referring to a distinct period of history, the time in which he and the audience were living.

In saying "the promise of this age", he is referring to the inspiring possibilities of that time period.