For most people, phoenixes symbolised rebirth.
How trivial, Harry thought, as he stared at Fawkes' ashes. How many times has the bird done that? How many times did it burn, live and burn again? Always waiting for the inevitable burning day, when it was forced to feel the agony of being burned alive. Never able to escape the vicious circle.
He wondered if that was why Fawkes tended to look so miserable and sad just before it happens. Maybe he has resigned himself to his fate. His death was unavoidable and the period of living in between was just a long wait for it.
For most, phoenixes symbolized rebirth.
For Harry, they were the epitome of endless death.
And sometimes, they were more kin to him than the people around him.