Mr Brook, now of Geraldine, was one of about 200 past and present pupils, parents, and staff, who gathered to farewell the school.
Afterwards, 65 attended a dinner at Carisbrook.
The school closes on Friday, after the board of trustees asked the Ministry of Education to close the school because of its falling roll.
On February 1, 1950, Mr Brook waited in the school corridor, with his small bag and packed lunch in tow, to be told where to go.
Everybody was "milling around", he remembered, and no-one seemed to know what they were doing.
After that, Mr Brook's primary school days were pretty typical of the 1950s: half-pints of school milk, no-nonsense school masters, cups of hot cocoa in the hall for a penny, and the dental nurse's savage foot-pedal drill were all vivid memories.
Ron Messer, of Dunedin, remembered the school being so full in the early days that a couple of classrooms were accommodated at a nearby church.
Corstorphine was created to absorb the demographic bubble created by the baby boom, so it was packed in the 1950s, he said.
Rosemary Meek, another first-day pupil at Corstorphine, remembered classes for about a year in a hall on Isadore Rd while the school was built.
At the new school discipline was strict, and Mrs Meek remembered not saying "boo to a mouse" in her effort to stay out of trouble.
It was a far cry from children now, who happily gave the adults orders, she said.
Farewell organiser and former deputy principal Paul Turnbull said the school's roll easily topped 600 in the 1950s and 1960s.
It had tailed off in the past 15 years largely for demographic reasons, he said.
The area's residents tended to be older and their adult children had moved away, not staying in the area to have children.
Mr Turnbull, who taught at the school between 1983 and 2001, said while Corstorphine was low-decile, it was characterised by a strong community.
Parents on Corstorphine's school board frequently went on to serve on their children's intermediate and high school boards of trustees, which was indicative of a strong interest in school affairs.
Saturday's big turnout was testament to the strength of the school community, he said.
Notable past pupils included artist Grahame Sydney, and former New Zealand basketball captain Glen Denham, neither of whom attended Saturday's farewell.
Board of trustees member Steph Derrett, who attended the school in the 1970s and early 1980s, said she did not agree with a claimed link between Corstorphine's falling roll and the Mongrel Mob presence in the suburb.
In April, police seized the Mongrel Mob's headquarters in Middleton Rd.
Mrs Derrett said children of Mongrel Mob families who attended the school were no different from other children.
In general, "mob kids" had not perturbed parents of other children.
Of her own school days, she said she made many good friends.
Board of trustees chairwoman Sheralyn Weepers said she was "absolutely devastated" by the closure, but the board had had to be realistic.
"How long do you go before you say enough is enough?"
The school roll dropped from 110 four years ago, to 17 at the start of 2010.
Principal Marion Carter said the seven pupils still at the school would have a special lunch with staff on Friday as a final farewell.
The children had had transition visits to their new schools and were well prepared, she said.
Office manager Kath Sturgeon said that after 21 years she was extremely sad the school was closing.
Staff had tried to maintain as normal an atmosphere as possible, after an exodus of pupils in term 1.
She had stayed at the school so long, even though it was a long way from her house in Pine Hill, because it was a special place: "It's always been a great school community."
