After careful consideration, my mind fell upon Princess Celestia and Princess Luna, and how, as immortal beings, they would be forced to witness the passing of countless friends over time.
I can only imagine that the most devastating blow for Luna would be the passing of her dear friend, Snowdrop, a blind pegasus whom Luna had befriended (before Luna had become Nightmare Moon), and who found the beauty in something as cold and bleak as snow.
Snowdrop gave everypony hope, especially Luna, who had been desperately trying to teach ponies to appreciate the night as she did.
But of course, when Luna became Nightmare Moon, she was imprisoned within the moon for one thousand years, and tragically, she never got to see her best friend again.
Snowdrop, as pure and kind as she was, was still a mortal, and passed away before Luna had a chance to say goodbye.
Remembrance is nothing short of a curse for Luna, missing her friend so dearly and unsure of what to do, but at the very least, she can find a bit of consolation in visiting Snowdrop’s memorial and decorating it with a bouquet of flowers. Snowdrop flowers, that is.
She sold her soul to the snowflake gods (which she created by making the first snowflake) for immortality, she had to create a cover story for her own death so it wasn’t know that she was immortal, for when the final snowflake fell the snowflake gods would be unleashed upon the world and only Snowdrop could defeat them.
why would she do that? and besides, it’s been over a thousand years, Snowdrop would still be long dead by the time Luna returned.
Unless she merely faked her own death
But Snowdrop isn’t the one who’d be reading it.