It is said that the first 24 years of the life of Shri Chaitanya Mahaprabhu are consisting of His childhood pastimes and also His pastimes in the Grhastha Ashram. So it is said this period lasted up til His 24th year of age. At that time He became Nimai Pandit and as Nimai Pandit He was extraordinarily learned, there was no one who was like Nimai. But Nimai's learning was not in the science of Bhakti, but rather Nimai was expert in Vedic grammar and study of logic in the Vedic literature. So in this way Nimai was known as a great scholar.
But the devotee's were not recognising Him as the Supreme Lord.
He was
the covert avatar.
The covert incarnation - The hidden incarnation of the Lord.
(HH KKS 31/07/2005)