Rav Aharon Kotler was once in Miami Beach on a fundraising mission and his talmid saw him writing and writing and writing, until the ink was finished and he asked for a new pen in order to write more. He had no sfarim in front of him. He was just writing, writing and writing.
The talmid asked him what he was writing. R' Aharon said that he was writing chiddushim that he had been mechadesh 40 years before and he never had time to write them down...
