Here's why:
* It was written on a piece of paper that was likely kept with Rizal's other personal belongings.
* He was executed in 1896, and his belongings were probably confiscated by authorities at the time.
* The poem wasn't published until 1898, after the revolution against Spain had begun.
The poem's journey to publication is interesting:
1. Rizal's friend, Ferdinand Blumentritt, received the poem from the priest who attended Rizal in his final hours.
2. Blumentritt shared it with the press in Europe, where it was published and quickly became a symbol of the Filipino struggle for independence.
So, while the poem wasn't "hidden" in a physical sense, its journey through the hands of his friend and into the public eye illustrates how it became a powerful symbol of resistance and national identity for Filipinos.