Old people often look back on the days of their youth.
Literal
Old-people [topic-は] often young times [possessive-の] things [object-を] reminisce.
しばしば ('often, frequently') is more literary than よく. 回顧する (かいこする, 'to reminisce') is a formal/literary verb that frames recollection as a gentle, contemplative act rather than mere dwelling. The register makes the observation feel sympathetic rather than critical.