Why are there so many references to time and numbers in the first part of the story?

Okay, I have thought long and hard about this. I really do love this story but have not come across this question in this context. I think time is very important because simply Santiago is running out of it. He is old and, more or less, alone. He has fished 85 times with no catch. Time is a theme here. Santiago was once young and verily; now he is old and worn. Reminders of time are everywhere, "Once there had been a tinted photograph of his wife on the wall but he had taken it down because it made him too lonely to see it." Numbers give definition to the concept of time. Age, number of fish, number of days without fish, Santiago's age, baseball, number of sharks after his Marlin....numbers define these factors and seem to give a sense of composition to the story and Santiago's life. I could be wrong but there it is!