He saved his strongest admission for the event itself.
"I've never wanted to win a fight this bad in my life," Mayweather (47-0, 26 knockouts) said of the bout at MGM Grand in Las Vegas against record eight-division champion Pacquiao.
Mayweather referred to the long-anticipated showdown as "the fight of the century," and said his mission to stage a fight pitting "the best fighting the best" came down to timing.
"We couldn't choose a better time," Mayweather said at the news conference. "This is a fight the world can't miss."
The world will also pay dearly for a bout that is expected to shatter pay-per-view and live-gate records.
Mayweather said earlier in the day that he expects to pocket "nine figures for 36 minutes of work," but he declined to elaborate.
Part of that has to do with unsettled pricing. Pacquiao promoter Bob Arum told The Times on Tuesday that he expects the pay-per-view price to be between $90 and $100, but it's not finalized yet.
Mayweather advisor Leonard Ellerbe of Mayweather Promotions announced seats inside the arena will be priced between $1,500 and $7,500 – an increase from the original $5,000 ringside-seat price that was discussed.
Ellerbe told The Times following the news conference that he hasn't established how many tickets will be available for sale to the public, adding that more ticket information should be distributed "in the next couple of days."
Mayweather struck a deal to get a 60/40 split of the purse with Pacquiao. Asked if he can estimate what Mayweather will earn for this bout, Ellerbe said, "We have a deal in place and Floyd's focus now is on winning the fight.
"The revenue is going to take care of itself. You don't chase money. You chase victory."
The match pitting the fast, elusive Mayweather, 38, against the well-conditioned, power-punching Pacquiao, 36, will answer which of the sport's top two pound-for-pound fighters will emerge as the fighter of his generation.
Earlier in the day, Mayweather predicted his boxing intellect would decide the outcome.
"I can figure a guy out instantly," he said.
Pacquiao has said he is "100%" confident of victory.
The news conference not only brought the two fighters together for a faceoff inside L.A. Live's Nokia Theater, it created interaction between Mayweather and his former promoter, Bob Arum. Their 2006 split created bitter tension that contributed to preventing the mega-fight from happening for years.
Arum said, "Hello, Floyd," upon his introduction, and Mayweather extended his hand for a shake.
“Everyone said with the animosity, you’ll never get this done,” said Arum, who credited CBS President and CEO
Arum then glanced to his right, where Mayweather's father/trainer, Floyd Sr., was seated, and, after years of critical words, referred to him as a friend and said, "We're all part of this big boxing family."
Some of the old tension was referenced after Showtime Vice President Stephen Espinoza said Mayweather "has kept every one of his promises" about wanting the Pacquiao fight after an initial negotiation that started in late 2009 crumbled over a drug-testing request made by Mayweather.
Arum chided Espinoza, "Well, Stephen, everyone has their own opinions," and looked at Mayweather.
"You missed me Floyd, didn't you?" Arum said.
Pacquiao trainer Freddie Roach said on stage, "We're in the toughest fight of our life," then quickly closed with, "we're going to kick his [rear]. Sorry, Floyd."
Arum introduced Pacquiao, who is from the Philippines, as a descendant of the fierce soldiers who fought against Japan in World War II, adding "the graciousness and kindness of Filipinos is exemplified by this man."
Pacquiao conceded financially to make the fight, and was eager to announce, "The fight is on. We will do our best to make you happy."
As he prepares for his 31st fight with Roach since 2001, Pacquiao said, "We're the longest team in boxing," a claim the Mayweather family trumps.
Floyd Sr. spoke earlier Wednesday of teaching his son boxing moves as a toddler in his crib, "and as God as I my witness," Floyd Sr. said he returned one day to see his son mimicking the moves.
A lifetime of training for the fight of a lifetime.