If there was one name that struck fear in generations of New Town Secondary School students, it was that of teacher "Tiger Lau".
Mr Lau Cheong Wong - who was given the affectionate nickname by students - joined in 1968, and stayed until 2005.
He was known as a strict, no-nonsense disciplinarian.
"It was just his presence," said former New Town student Philip Wu, 47. "You knew not to go near him if you saw him. But after a while, we realised that he had a caring side too."
When the school first started in 1965, it had an intake of more than 1,800 students in 45 classes, across Secondary 1 to 4.
But even with the large cohort, teaching was a "wonderful" job then, 68-year-old Mr Lau recalls.
Teachers had fewer administrative duties and spent more time getting to know their charges.
"On weekends, we would plan hiking trips with the students and other teachers," he said. "Back then, we had better relationships with the students."
Mr Lau taught maths and science until the 1990s, when schools started jumping on the IT bandwagon.
"Some teachers who had trouble adapting to IT left the job," he said.
But he picked up Microsoft Word, Excel and Powerpoint quickly, and taught computer applications, a subject offered to Normal (Technical) students.
Mr Lau, who faced the challenges of students who are less academically inclined, said: "Those in the Normal Tech stream needed a fierce teacher to discipline them. But, once you won them over, they would do anything for you."
He recalled one tough student who offered to help him "settle problems" if he ever ran into any.
Mr Wu, who studied at the school from 1981 to 1984 and served as a prefect, describes New Town as a microcosm of society with students from all walks of life.
He now actively contributes to his old school and has opened his firm, media company Grid Synergy, to allow his juniors to do internships during school holidays.
The school's current principal, Ms Wong Yu Yuh, said: "We are looking for ways for our alumni to contribute to and collaborate with the school.
"On top of ensuring that students do academically well, we also hope to support our students' interests as much as we can."