In a rare public speech today, Castro admitted as much. Take it straight from El Caballo's mouth.
"I'll be 90 years old soon," Castro said today. "Soon I'll be like all the others. The time will come for all of us, but the ideas of the Cuban Communists will remain as proof on this planet that if they are worked at with fervor and dignity, they can produce the material and cultural goods that human beings need, and we need to fight without
Castro spoke to mark the announcement that his brother Raúl would continue to serve as secretary of the Communist Party for another five years despite the fact he's expected to step down as president in 2018. Through the role, Raúl will continue as the de facto leader of the party and country. José Ramón Machado will remain in his role as second in command.
Though, advancing age is not a problem Fidel faces alone. Raúl is 84, and Machado is 85. Much of the rest of the party's leadership is also graying.
Notably, new members selected to the party's 15-member ruling council weren't particularly young or representative of reform. However, the country's 55-year-old vice president, Miguel Díaz-Canel, is widely expected to succeed the younger Castro in 2018.
Fidel's comments seem to be less an admission that he's expecting to kick the bucket and more of a statement of common sense. With so much change coming to the island, Castro wants to send the message the he believes the Communist Party will continue to rule long after he's done.
Fidel Castro's appearance is the second time he's popped up in public this month. He also spoke to schoolchildren April 8 but before then had not been seen since July 2015.