As Wales's longest-serving school inspector, Alun Morgan has grown used to telling headteachers things they do not always want to hear.
Mr Morgan is preparing to retire next year after a 29-year career in which he has inspected more than 1,000 schools.
But before then, he has a final piece of advice: schools must improve their self-evaluation if they want to get top marks under the new Estyn regime.
Mr Morgan told TES Cymru that poor self-evaluation was one of the main weaknesses of failing schools, with staff too often unaware of how bad things had become.
Estyn's new framework, which comes into force from September, will make inspections shorter and place a greater emphasis on self-assessment and evaluation.
Speaking ahead of the launch of the framework later this month, Mr Morgan said: "I frequently come across schools that don't think they're bad. There's sometimes an element of burying heads in the sand, but it's mostly because their self-evaluation is weak.
"Effective self-evaluation is very important, and it will take on even more significance now under the new framework. It's essential schools get it right."
Mr Morgan has seen many educational and political changes during his career, including the introduction of the national curriculum and GCSEs, the splitting of the English and Welsh inspectorates and devolution.
He said that the introduction of Estyn's new framework would change the nature of inspections in Wales in an "extremely positive" way. "It will lead to shorter, sharper, more focused inspections and reports," he said. "Our hope is that schools will feel this is something done with them, and not done to them."
Mr Morgan became an inspector little more than seven years after starting his teaching career in 1975.
Having decided that school leadership was not for him, he instead opted for a career that kept him in the classroom and joined Her Majesty's Inspectorate for Schools and Colleges, which was then part of the Welsh Office of Education based in Swansea.
In the following three decades, during which he has never taken a day off sick, Mr Morgan reckons he has visited around 60 per cent of Wales's 1,460 primary schools and around 70 per cent of its 220 secondary schools.
Memorable moments include interviewing a teenage Catherine Zeta Jones while inspecting Dumbarton House school in Swansea.
"I like working with schools in areas of disadvantage and those in more challenging environments," he said. "I think it's partly sentimental; I come from a working-class background and I like to see opportunity for young people."
Despite planning to retire, Mr Morgan hopes to stay involved in education in some capacity and said he would be "bored stiff" otherwise.
"I think the biggest challenge facing education is raising the achievement of pupils from disadvantaged backgrounds," he said.
"However, I do feel that teaching has evolved very significantly and standards have improved. There are far more good schools now than when I started."
A 29-year career
- Alun Morgan was born in Merthyr Tydfil in 1947. He graduated from Swansea University with a degree in history and politics.
- In 1975 he joined Treorchy Comprehensive School teaching history and the British constitution.
- In 1979 he became head of history and politics at Tonypandy Comprehensive School.
- In 1982 he joined Her Majesty's Inspectorate for Schools and Colleges as a secondary HMI.
- Mr Morgan is now lead inspector for humanities with Estyn, covering history, geography, sociology and politics.
Original paper headline: Veteran inspector's advice to schools: take a long, hard look at yourselves