Is a person REALLY great ?

"The man who does not read good books has no advantage over the man who cannot read them."
- Mark Twain (1835-1910)


Does a person become great because he is destined to be ? Does a person's ability make him reach his greatness ?
OR
Is it the events in his/her life that make him so ?

I have more or less been seeing people achieving greatness because the events made them so, the surroundings in which they grew up were conducive for becoming so.

Recently, i read Biography of Indira Gandi by Pupul Jaykar, and am reading General Mckinshaw's autobiography.
What is it that makes a great person / an icon ?
As in cricket they say, the timing needs to be perfect to hit the ball !

Is it all the timing and the up bringing of the person that matters ?

All that matters is " Being at the right place at the right time !"