Which details ? ........................
The speaker had a specific identity. He was A.H.'s friend and this was the way he mourned him. No one else mourned him with those words. No one else shared the same experiences with A.H. The I may be known to the reader but that doesn't matter. The I is expressing his personal grief in his poems.
Your answer would be “The most memorable trip was when my brother and I encountered a bear.”
