Hesketh Pearson, The Smith of Smiths, being The Life, Wit and Humour of Sydney Smith
(New York: Harper & Brothers, 1934), p. 319:
In June  he was laid up with the gout and one of his callers, Thomas Moore, was amused and surprised to find him studying French, a copy-book open upon the table, with all the verbs, their moods and tenses, written out neatly in his own hand. Moore thought it an odd pastime for a septuagenarian.
I don't find it odd at all, and I hope I have enough of my wits about me in my later years to do something similar.