Below, you'll see any text that was highlighted with comments from the reviewer.
Message to Readers
I would love to know how this letter would make you feel!
I found it intriguing that such a universal theme was addressed, but what really stood out for me was, "I never knew that I would write a letter to an immortal recipient." because letters suggest a correspondence between two, but as implied, Change will probably receive thousands of letters, outliving us all. What difference this letter makes, then, is what the writer has reflected on and how the writer charts their change after writing this, which is ironic, in a way.
What inspired the kind of personality you assumed for Change when you wrote this?
This piece is unflinchingly honest and sincere, always reflecting on what has happened -- not blaming, but evaluating. I felt that this is what marked the maturity of the writer.
I feel that the writer's tone was consistent and engaging throughout, it lent a strong personal voice to the letter. I would suggest adjusting the flow of the letter, such that the feelings experienced by the author is chronological and readers can chart the growth Change has made within you (pardon the pun). The unexpected magnanimity of Change can be also placed towards the end to surprise the reader, although I only suggest this as a consideration. I believe it is fine where it stands now.
All the best in writing and may the force be with you on the long road ahead. :-)