Mr Brown, who has a BCom in accountancy from Otago, was commenting yesterday in an address at the university's latest graduation ceremony.
More than 420 graduands graduated with degrees and diplomas in science, commerce, consumer and applied sciences, physical education, and surveying at the Dunedin Town Hall ceremony.
"The world is going through a financial meltdown of such magnitude that exceeds anything most of us have experienced in our lifetimes.
"It has been described as a `Once in 100 years financial tsunami'," Mr Brown said.
"I clearly remember as a third-year accountancy student 45 years ago, being taught simple, basic rules of sound financing, which today should still apply, perhaps with some modification, but those rules seem to have gone right out the window."
When things were on a roll, it was easy to believe good times would surely continue and the reasons for past failures were no longer relevant in a changing world.
But history had a way of repeating itself.
A writer, James Miller, had once described a major collapse as being driven by "the golden baits of avarice, the airy hopes of projectors and the wild enthusiastic dreams of speculators".
That statement might well be applied to today's "global financial mess", but had been written in 1845 to describe The South Sea Bubble financial scandal in 1721.
Some Otago graduates would become leaders in finance and business.
He advised them to take some risks but also urged them to also learn from the lessons of the past and present.
"Remember that if something seems too good to be true, it will invariably be very good for a few, but in the long run very costly, both directly and indirectly, for a great deal more."
It had been a "wonderful privilege" to have been Otago University's 17th chancellor.
His work as chancellor, and his long involvement with support organisations involved with two illnesses had taken him out of his comfort zone and helped shape him into "who I am now as a person", he said.
Mr Brown, who completes his term as chancellor at the end of this month, was capped with an honorary doctor of laws degree by his successor, pro-chancellor John Ward.
