"We are upset, I really thought Peter Obi would be elected," said Nikodemos Daniel, a 27-year-old motorcycle driver in Onitsha, in Anambra State.
Saturday, many young people across the country turned into ardent defenders of democracy remaining for hours, sometimes in the rain, to ensure vote transparency.
The Independent National Electoral Commission (INEC) said the February 25 election would be more transparent than past votes tainted by accusations of rigging and ballot-buying.
But long delays in voting and slow delivery of the results upset many and stoked suspicions of fraud.
INEC said technical difficulties caused problems but insisted the vote was free.
"This time, we thought it would be different," said Osaki Briggs, 25, a photographer from the southern state of Rivers.
He said the election was "depressing," just like previous ones marred by accusations of fraud.
"Everyone expected an online transmission of results from polling units to portal... Only, after voting, we heard the portal crashed," said Orison Omega, 23, an Abuja student.
"Which cannot be true. There could only be a hidden agenda."
"How can a sick man who can't stand on his own or make a speech (...) be declared the winner?" asked Jennifer Dike, 28, in reference to concerns over Tinubu's health and age - worries his party dismisses as unfounded.
For her, Tinubu will not be the president who will "deliver" Nigeria from corruption, hunger or poverty.
"I'm so sad. No wonder young people are leaving the country in large numbers these days."
For the social media-connected youth of the south, Obi precisely embodied this desire for change and something better.
But analysts doubted the ability of the candidate of the small Labor Party to amass votes beyond his stronghold and in particular in the Muslim majority north.
The Labor Party announced Wednesday that it plans to file a court suit challenging the outcome of the election.
But for now, life goes back to normal in Onitsha in Obi's home state as elsewhere with Nigerians getting back to work.
"If he is a candidate, Peter Obi will win the next one," said Chukwu Michael.