Timing the perfect museum visit

From Humanities magazine: "'Two hours maximum' is what Lisa Hanover of the James A. Michener Art Museum in Doylestown, Pa., advises for the length of a museum visit. Fatigue sets in earlier for others: Hower suggests 45 minutes, allowing additional time to visit the café and museum store, while another official suggests an hour and a half for a first visit, a 'more focused' hour next time, and 45 minutes for an even more focused third visit. Aside from breaking for lunch, 80-year-old sculptor George Anthonisen puts no time limit at all on his visits to the Met with his wife, Ellen. Figure this one out for yourself, then, based on stamina and timetables."