Education reform is one of the most difficult things to achieve in government, according to Tony Blair.
The former Labour prime minister, who made education a key focus when he first took power in 1997, said that it is "hell" to push through change.
In a wide ranging debate at the Global Education and Skills Forum in Dubai that covered the upcoming US election and the EU referendum, Mr Blair refused to give his opinions on politicians such as potential Republican presidential candidate Donald Trump and Labour leader Jeremy Corbyn.
But he agreed that there is now "populism" in politics, both from the right and left wing.
The former Labour leader said it was his experience that education change "is probably one of the most difficult things you do in government".
"You have major interests that often stand in the way of it," he said.
"My experience of reform is that everybody is in favour of reform in general, it's just that in particular, they're usually not, especially when the reform comes to them."
He added that he wished he had understood at the start of his time in office that "particularly with education reform, when you first propose it, people tell you it's a terrible thing. When you're doing it, it's hell, and after you've done it, you wish you'd done more of it."
Mr Blair also suggested that he was not against profit in education, as long as children are being educated well.
Asked if it is acceptable to make money out of education, he said: "Provided you're educating the kids well. The single most important thing is that they get a decent education.
"In our state system in the UK we don't have a for-profit part to it. But I personally think if you're starting now, particularly if you're in a developing country, and someone can come in and run schools effectively or individual schools. This is just my experience in government that the benefit of the public sector is that it helps those who need help.
"The problem is that it's not good at innovating and I think if you have a range of providers, it allows you to see what might be possible and it allows people to adapt and adjust."
Later, the panel, which also included Sir Martin Sorrell, head of advertising firm WPP, was asked about the rising appeal of politicians such as Mr Trump
Sir Martin said: "They are all of the same ilk. Despite the fact they come from the right wing and the left wing, they are all populists."
The upcoming referendum on Britain's membership of the EU will get into difficult territory around immigration, he argued.
"It stems from in my view, from 2008. It stems from that precipitous weekend in September in 2008 when we looked into the economic abyss and for eight years, the world is still running at sub-trend growth rates with very little inflation, growth is tepid and it is a tough environment, with relatively high levels of unemployment and youth unemployment."
Mr Blair said: "There is a populism of left and right. There's a lot of anger about. Anger is all very well but it's answers that deliver results."
He added: "I have no idea what's going to happen. When I look at politics today, I am not terribly sure that I quite understand it."
Anyone who wants to push back against populism needs to make the argument against it, Mr Blair said.
"For example, this whole debate around migration is really difficult for people. There is no point in just dismissing it as prejudice - although a lot of it is prejudice. It's also real anxiety for people about the world changing, particularly if they think their incomes are stagnating and they aren't really getting anywhere in life, then this becomes an easy thing to gravitate to."
Education is important, Mr Blair said, for example it is important that refugees are educated and that host countries are educated about the people arriving.
"The answer to someone who is unemployed in a country like mine or anywhere else in Europe, is not to blame migrants for having taken your job, but is to get the education and the skills necessary in order to be able to operate in the modern world."