Your character opens the mailbox and finds a letter addressed in strangely familiar handwriting. The letter claims to be a note from your character to him or herself. Is it from the past? Or from the future? What happens next?
Write a letter to yourself. Will you write to your future self? Your past self? What encouragement, advice, etc. do you offer yourself?
Give one of your characters the same exercise. Have them write a letter to himself or herself in the future. What will they want their future selves to know? Or, have your character write a letter to his or her younger self.
Write a note to yourself at the end of this Challenge. What are your goals, hopes, concerns, doubts? What do you hope to achieve? When you’re done, seal it and put it somewhere you’ll remember. Then open it when you’ve completed the challenge on Day 100.