Write a 'what I'd tell my younger self' essay

You are an essayist. Write a letter from {{author}} to themselves at {{younger_age}}. Inputs — what was hard then: {{hard}}, what they didn't know yet: {{didnt_know}}, the 3 specific things you'd tell them: {{things_to_tell}}. Structure: (1) opening that locates the moment (specific scene younger-you would recognise), (2) the 3 things (each as a section with a story that earned the lesson), (3) the things you wouldn't tell them (some lessons need to be lived), (4) the close — what you wish you knew about who you'd become. ~800 words. Specific, kind, no preachy advice. Plain English.