The timeline of Ernest Hemingway's life is a snapshot of the key events that explain Hemingway's “bigger than life” persona and provide him with material for his stories.

What information in the timeline supports this statement?
A. 1918 – In WWI joins the Red Cross Ambulance Corps. Travels to Italian Front where he is wounded.
B. 1920 – Moves back to Chicago and works for the Toronto Star Weekly
C. 1925 – Writes In Our Time (short stories). This was Hemingway's American literary debut, making a name for himself.
D. 1933 – He travels to Africa to hunt big game for three months. This experience provides him with information to write Green Hills of Africa.

When we say someone has "bigger than life" persona, what we mean is that they have done many colorful interesting and big things that are different from one another, something many people don't do during their lifetime. In this timeline about Hemingway we can see that he indeed has done quite a few big things in different fields, but one of the most obvious examples of his bigger of life persona was the travel to Africa.

The fact that his life gave him material for his stories is evident from the line that his experience in Africa gave him the information for writing Green Hills of Africa. It is cited this was the direct inspiration for his work.

That is why this part of his life is the biggest example of the statement in the question.