Shehu said the weight of expectations from Nigerians has blinded them from recognising the president's impact.
In a statement released by the president's aide on Sunday, April 22, 2018, he said the president gained power off the back of a lot of expectations whose weight has blinded many from recognising the impact he's making in governance.
He wrote, "For President Buhari, who won with massive votes in 2015, his major challenge is to do as well as he did, or even better. He came to power with a lot of expectations and Nigerians had, justifiably placed very high hopes on him.
"As we said sometimes back, he as a consequence, has became a victim of the tyranny of expectations. The weight of unrealistic expectations has evidently blinded many of the people from seeing the revolutionary changes happening across the nation.
"Nigerians expected him to undo the damage in several decades of misgovernance and naturally, many are already feeling frustrated that he hadn’t done that in three years."
Shehu also attacked the opposition People's Democratic Party (PDP) and the "so-called" Third Force for failing to provide a decent alternative to President Buhari to contest in the 2019 presidential election.
He alleged that the opposition is united by scaremongering and not by a decent ideology that prompted Buhari's victory in 2015.
He said, "The problem with our opposition is that beyond fault-finding, they are unable to give or innovate a vision of their own on how they can make the nation better.
"A so-called Third Force has failed to get political traction since it birth. This is understandable, given that they have promised to give the country everything that is new but have so far produced no new faces, no new ways of doing things. Certainly, there is no face that can be called the President of Nigeria.
"For the Peoples Democratic Party (PDP) parading itself on the glory of being the largest opposition, the party has not less than 10 leaders acutely ambitious to rule Nigeria. It will take them minimally two to three terms of presidential tenure, that is eight to twelve years to reinvent the party.
"Looking at the entire opposition landscape, it can be said that they cannot be united by ideology, the type that made the pre-2015 opposition fuse into a formidable challenger that pushed an incumbent out of office. There is in no way therefore, they can choose leaders with unanimity.
"What then they have taken to, is scaremongering by fanning ethnic and religious divisions among the minorities especially in the Middle Belt where hundreds of innocent citizens are confronted with violent death.
"Before they take the words out of my mouth, let me state that the spate of those killings are tragic and unacceptable. They ought not happen and I'm aware of how sad the Presidency is about these unfortunate goings-on. And there is so much that is being done to end the killings.
"More, however, could still have been achieved if there is cooperation extended to the security agencies by everyone, and by everyone, I mean especially the political opposition.
"A political warlord recently ordered the provocative stoning of a Nigerian Air Force personnel as their chopper landed in a Northeastern state."
Shehu also highlighted the president's achievement in the area of security (most especially in curtailing the activities of Boko Haram), the economy, particularly in the area of agriculture, as well as power supply and infrastructure.
The presidential aide concluded by declaring that President Buhari has not given anyone an excuse to not vote for him in next year's election as he is motivated to ensure that the gains made from 2015 are not asted.