"That says more about my age than anything else," joked the 92-year-old head of the faith's Quorum of the Twelve Apostles. "Let's just put it this way: I no longer buy green bananas."
Speaking from the Marriott Center at LDS Church-owned Brigham Young University in Provo, Nelson pointed to several of those leaders, viewed as "prophets, seers and revelators" by devout Mormons, including Thomas S. Monson, the 89-year-old who currently oversees the Utah-based faith.
He emphasized Monson's longtime church service, being named as a lay bishop at age 22 and a full-time apostle at 36, along with his kindness and caring to individuals.
Nelson said Monson, long known for making unannounced visits to hospitals and homes, has provided an example for rising generations of LDS leaders by showing through his actions that "taking care of people is always more important than management of time or meetings or schedules."
Last January, during a similar address to millennials, Nelson proclaimed that a November 2015 church policy branding gay Mormon couples as "apostates" and barring their children from baptism until they turn 18 reflected the "will of the Lord" as given to Monson.
On Sunday, Nelson counseled his young charges to "live by every word that proceedeth " from the Almighty, emphasizing that divine decrees are incontrovertible.
"What God says is right is right," he declared. "What God says is wrong is wrong."
Nelson then invited young Latter-day Saints to set aside time each week to study the Bible and Mormon scriptures to learn about everything Jesus said and did.
"The only way to be a true millennial," he said, "is to be one of his true disciples."
Nelson's wife, Wendy W. Nelson, spoke before her husband and offered tips about love, sex and marriage.
"Think of me as your Aunt Wendy," she told her audience of single Latter-day Saints.
A former professor of marriage and family therapy, she advised Mormon millennials to pursue personal purity and drew distinctions between "worldly sex" and "God-ordained marital intimacy."
"Pornography," she warned, "will prevent you from experiencing the most marvelous kind of intimacy."
But fidelity, respect and "purified passions" within marriage, she added, will pull couples closer to each other and to God.
"The Lord wants a husband and wife to partake of the wonders and joys of marital intimacy," she said. " ... Marital intimacy is sacred. In fact, a husband and wife can be drawn closer to God when joined in true marital intimacy."