“Waste” is probably the wrong word. Even moments that would not be considered wasted by most people, he saved for Torah study.
For example, he did not visit the cemetery on the yahrzeit, the anniversary of the death, of his father. (I was told this when his mother was still alive; presumably, he did not visit her grave, either.)
The person who told me this was Rabbi Noah Heisler, a rabbinic judge in Jerusalem.
During the 1970s, I drove Rabbi Heisler and his father to visit three rabbinic eminences during the intermediate days of Passover and of Sukkot: Rabbi Yosef; Rabbi Yosef Shalom Eliashiv, who died a year ago at 102; and Rabbi Bezalel Zolti, the chief rabbi of Jerusalem, who died at 61 in 1982.
No doubt, many will look back upon the era in which these three scholars — each one a mind of breathtaking scope — served together as the judges on Israel’s highest rabbinic court as a golden age.
During these holiday visits, Rabbi Yosef exchanged brief greetings with and extended blessings to thousands of visitors, though the visits were never rushed.
With learned rabbis, such as the Heislers, Rabbi Ovadia Yosef also traded a few words of Torah. These visits were a rare opportunity to have a few minutes of his time in order to clarify, at least to an extent, complicated halachic matters.
I also remember that once Rabbi Noah Heisler raised an issue and Rabbi Yosef referred instantaneously to a responsum on the matter by Rabbi Joseph Saul Natanson, a 19th-century Ashkenazi scholar.
Rabbi Yosef’s recall was legendary.
He knew by heart literally thousands of learned works of Jewish law.
He had a photographic memory.
And he never stopped using it.