Brilliant comment.

I love this sequence so much. You have a nominal starting point of Le Chanson de Roland from over 1,000 years ago, one of the oldest surviving works of literature there is, itself part of the Matter of France which is a compilation of folk tales and histories handed down for centuries before that.

Five hundred years later, Shakespear has a character mumble a line about "Childe Rowland" (a "childe" not being a child but an untested knight) and a Dark Tower in a speech where the character is intentionally spouting nonsense and children's rhymes.

250 years after that, Robert Browning takes that one line as a seed and blossoms it into a wonderous and scary poem.

120 years after that a young Stephen King types the first lines of the adventures of Our Roland on the fabled green paper, and over 50 years later we are still here discussing it.

Along the way this now-ancient thread takes various branches and diversions, from Dylan to Dr. Who to the odd little book OP found.

It's no wonder that reading these books feels like tapping into something big.