Why is the old man reluctant to leave?

"The Old Man at the Bridge" by Ernest Hemingway takes place in the Ebro Delta during the Spanish Civil War in 1938. The inhabitants of villages in a section of countryside are being evacuated due to enemy incursion. The narrator is a soldier who explains his mission: "It was my business to cross the bridge, explore the bridgehead beyond, and find out to what point the enemy had advanced." When he returns, he spots an old man from a town called San Carlos sitting by the side of the road.
Hemingway suggests several reasons why the old man is reluctant to leave. At first, as the story says, "He was too tired to go any farther." As the narrator questions him, the old man says that he had to leave some animals, which turn out to be two goats, a cat, and four pairs of pigeons, behind. He is concerned that the animals will not be properly taken care of. When the narrator suggests that the old man can get on an evacuation truck going to Barcelona, he is reluctant because he says he doesn't know anyone there. Ultimately, the real reason the old man is reluctant to move on is because San Carlos is his home and he has never known anywhere else. This is reflected in this passage:

"Where do you come from?" I asked him.
"From San Carlos," he said, and smiled.
That was his native town and so it gave him pleasure to mention it and he smiled.

The tiredness, the concern for the animals, and the lack of desire to go to faraway Barcelona are all part of the old man's love for his native town and his reluctance to leave it. In plain prose, the short story illustrates the sad plight of simple refugees forced to flee from the horrors of war.