Adi Shankaracharya  (507-475 BC)

अष्टवर्षे चतुर्वेदी द्वादशे सर्वशास्त्रवित्।
षोडशे कृतवान् भाष्यं द्वात्रिंशे मुनिरभ्यगात्॥

ashtavarshe chaturvedi dvadashe sarvashastravit.
shodshe kritvan bhashyam dvatrinshe munirabhyagat॥
At the age of eight he became a master in 4 Vedas and at the age of twelve he became a scholar of all scriptures.
In the sixteenth he wrote a commentary and in the thirty-second attained Brahma Siddhi Mukti.