Gulf News Puzzler: How Old is a "Boy" in India?

You are only as young as you feel or as the old timers call you.

The GCC’s newspaper of record, the Gulf News, had an article under the headline “Indian boy who sells snacks cracks difficult GATE exam in first attempt”. 

AA expected to read the inspiring story of a precocious 11 or 12 year –old “boy” who cracked the GATE.

Instead to AA’s surprise, Mr. Shah appears to have completed his undergraduate studies and is ready to move on to graduate school.  Yet, as per the article, he remains a “boy”, “young boy” or “youngster”.

  

Obviously, this must be a cultural thing.

How old does Mr. Shah have to be before he’s called a man? 

Or to stop being called a "young boy" or "youngster"?  

Or perhaps “How many roads must a man walk down before you call him a man?”

Paging R.A. Zimmerman.