Conversation so far:
who wrote the tune to twinkle twinkle little star
The melody of “Ah, vous dirai je, Maman” was published without words in Les Amusements d'une Heure et Demy in 1761. Although attributed to Boüin, the composer's identity is unknown.
How many versions of Twinkle Twinkle Little Star are there
In 1778, Wolfgang Amadeus Mozart composed a set of twelve variations on the theme “Ah, vous dirai je, Maman” for the piano

Question: How old was the composer in 1778
Self-contained rewrite: How old was Mozart in 1778