Answer and Explanation:
Santiago feels that no man is alone when he is at sea, because he knows that the sea is full of creatures and that when a man enters that environment, he becomes one of those creatures, as he faces the same dangers and reaps the same benefits. Therefore, this man becomes a sea creature and is accompanied by a number of other sea creatures, who will never leave him while he is at sea. He feels united with the creatures of the sea and supported by them at the same time. This feeling of belonging to the sea and the creatures that inhabit it is an inner reflection of Santiago, which is extended to any place in nature, as we can see through his dreams of lions, as he associates youthfulness, strength and behavior that he already had a day.
It is important to remember that Santiago is a character in "The Old Man and the Sea", a book that shows how an extremely strong fish, stimulates reflections on life, death, youth and time to Santiago, an old fisherman, tired and no luck.