Filippo Tuccio, 35, said he came from Venice on an overnight train to view Benedict's body.
"I wanted to pay homage to Benedict because he had a key role in my life and my education," Tuccio said.
"When I was young I participated in World Youth Days, he said, referring to the jamborees of young faithful held periodically and attended by pontiffs. Tuccio added that he had studied theology, and "his pontificate accompanied me during my university years."
"He was very important for me: for what I am, my way of thinking, my values," Tuccio continued.
Among those coming to the basilica viewing was Cardinal Walter Kasper, like Benedict, a German theologian. Kasper served as head of the Vatican's Christian unity office during Benedict's papacy.
Benedict left an "important mark" on theology and spirituality, but also on the history of the papacy with his courage to step aside, Kasper told The Associated Press.
"This resignation wasn't a sign of weakness, but a sign of strength, a greatness because he saw that he was no longer up to the challenges of being pope," Kasper said.
Kasper, who was among the cardinals who elected Benedict to the papacy in 2005, added that the resignation gave "a more human vision to the papacy: that the pope is a man and is dependent on his physical and mental strengths."
Public viewing was set for 10 hours on Monday, and 12 hours each on Tuesday and Wednesday before Thursday morning's funeral, which will be led by Pope Francis, at St. Peter's Square.
As Benedict desired, the funeral will marked by simplicity, the Vatican said when announcing the death on Saturday.
Workers on Monday were setting up an altar in the square for the funeral Mass. Also being arranged were rows of chairs for the faithful who want to attend the funeral. Authorities said they expected about 60,000 to come for the Mass.
On Monday, the Vatican confirmed widely reported burial plans. In keeping with his wishes, Benedict's tomb will be in the crypt of the grotto under the basilica that was last used by St. John Paul II, before the saint's body was moved upstairs into the main basilica ahead of his 2011 beatification, Vatican spokesman Matteo Bruni said.
At two sides of the piazza's colonnade, viewers went through the usual security measures required for tourists entering the basilica - passing through metal detectors and screening bags through an X-ray machine.
"I think his main legacy was teaching us how to be free," she said. "He had a special intelligence in saying what was essential in his faith and that was contagious" for other faithful. "The thing I thought when he died was that I would like to be as free as he was."
While venturing that the shy, bookworm German churchman and theologian and the current Argentine-born pontiff had different temperaments, Ferrante said: "I believe there's a continuity between him and Pope Francis and whoever understands the real relationship between them and Christ can see that."
An American man who lives in Rome called the opportunity to view the body "an amazing experience." Mountain Butorac, 47, who is originally from Atlanta, said he arrived 90 minutes before dawn.
"I loved Benedict, I loved him as a cardinal (Joseph Ratzinger), when he was elected pope and also after he retired," Butorac said. "I think he was a sort of people's grandfather living in the Vatican."
With an organ and choir's soft rendition of "Kyrie Eleison" ("Lord, have mercy" in ancient Greek) in the background, ushers moved well-wishers along at a steady clip down the basilica's center aisle.. Someone left a red rose.
A few VIPs had a moment before the general public to pay their respects, including Italian Premier Giorgia Meloni, the far-right leader who in the past has professed admiration for the conservative leanings of Benedict.
Italian President Sergio Mattarella also came to view the body. The Vatican has said only two nations' official delegations - from Italy and from Benedict's native Germany - were invited formally to the funeral, since the pope emeritus was no longer head of state.
Sister Regina Brand was among the mourners who came to the square before dawn.
"He's a German pope and I am from Germany," she said. "And I am here to express my gratitude and love, and I want to pray for him and to see him."