John Howard, Michael Kirby and Andrew Scipione are old boys but not from the networks usually associated with Sydney's private schools.
Rather, the former prime minister, the retired High Court judge and the NSW Police Commissioner are among the extensive list of high profile alumni of NSW public schools.
And they are are not alone. NSW public schools have produced Olympians, premiers, Oscar winners, Nobel laureates and artists, but unlike the long-established old girls and old boys networks that retain strong links with private schools, public school graduates often leave their past behind.
As part of a new project, the NSW Department of Education is encouraging schools to form alumni associations to bolster the reputation of public schools and prevent the migration to private schools.
"Famous or noteworthy former students are a great advertisement for public education, and specifically your school," a new document being sent to principals says.
The department urges schools to have a database and tracking method for their alumni so they can invite them to "significant school events, to give out awards at presentation nights, or to speak to students about careers and the merits of hard work".
But, unlike the hefty financial contribution many old girls and boys make to their former schools, the document does not offer any tips on how to convince the public school graduates to donate to their alma mater.
To celebrate 60 years of Education Week, some of the most prominent graduates of the state's school system, including TV presenter Lisa Wilkinson, human rights barrister Geoffrey Robertson QC and public health professor Stephen Leeder recorded video messages about their school experience for the state's 700,000 students.
And on Wednesday, Commissioner Scipione returned to his old stomping ground of Sir Josephs Bank High School at Revesby. He told students the school's motto semper ardore (''ever zealous'') and his inspiring teachers had stayed with him long after he traded his school crest for a police uniform.
"I can't tell you who the education minister was in 1971. I can't tell you who the local member was. But I can tell you the name of some of my favourite teachers," he said. "They impacted on my life and you will remember them forever."
The school had changed in 40 years, the commissioner said, with new buildings dotting the grounds and the M5 motorway encroaching on former football fields. But retracing his steps still brought back warm memories. "You can almost smell the fabric of what you enjoyed," he said.
Commissioner Scipione, who was a soccer player, surfer and woodwork enthusiast in his school years, said he was a well-behaved student who managed to avoid landing in then-principal William Barter's office. But he recalled a certain school administrator who "loved trains" and one muck-up day found his office covered in railway memorabilia and papier mache carriages.
The commissioner, for his part, denies any role in the mischief. "I was never that inventive," he said. "You had to be good at art-type things for that."