When Dr Sorinder Singh, 65, began practising medicine in 1980, the general practitioner had hardly any elderly patients.
Thirty-five years on, he still works out of the same spartan clinic at the foot of a Housing Board block in Marsiling.
"I've grown old and so have my patients," the genial father of three grown-up children says, with a laugh. Roughly a third of his patients are in their 60s or older. Many come in wheelchairs.
To better manage his geriatric patients - he has treated centenarians and his oldest patient today is 99 - Dr Singh will soon complete a one-year Diploma in Geriatric Medicine at the National University of Singapore (NUS). He is currently the university's oldest student, out of nearly 70 people aged 50 and above who are enrolled in various courses.
At a time when many of their peers are dreaming of scaling the next career peak or thinking of retirement, scores of older Singaporeans are returning to university.
Figures from four universities here show that more than 700 students enrolled in diploma and degree courses are aged 50 and above.
The vast majority - more than 80 per cent - attend SIM University (UniSIM) and Nanyang Technological University (NTU). The former has seen enrolment numbers among its seniors double in just five years.
Experts say that these numbers may well rise further as younger, better-educated cohorts enter the second half of their lives.
Some, like Dr Singh, do it out of pragmatism and a desire to do better in well-established careers. Others are driven by passion, pursuing long-treasured dreams. Yet others do it to jumpstart a second career.
As he frets about how he has done in his examinations - his final exams were held yesterday - Dr Singh says he is glad he went back to school. "I learnt the basics of wound care and about the many new community resources for older patients," he says. "This will definitely help me look after older patients better, especially as they age at home."
The oldest student at NTU, meanwhile, is cut from a very different cloth. Stella Kon, 71, the award-winning playwright, novelist and poet, is pursuing a Master of Arts degree partly by research. The grandmother of six is best known for her one-woman play, Emily Of Emerald Hill, about the life and times of a dominating Nyonya matriarch.
Ask why she is seeking a master's degree in creative writing after a successful lifelong love affair with words, and she breaks into verse, quoting Irish poet W.B. Yeats' Sailing To Byzantium about the agony of old age and the intellectual and spiritual pursuits required to remain vital:
"An aged man is but a paltry thing,
A tattered coat upon a stick, unless
Soul clap its hand and sing, and louder sing
For every tatter in its mortal dress..."
She has especially enjoyed a course on the history of literary theory and criticism - right from the Greeks to modern times - and is getting her supervisor's help with her next personal project: scripting a musical on the life of physician and social reformer Lim Boon Keng.
"As a mature student, I found that while the brilliant young graduate students had deeper knowledge of their subjects than I did, I did have a wider general knowledge of the field - as I have four decades more experience than most of them," she says, sitting in the living room of her elegant book-filled HDB flat in Owen Road. "I could see some connections they might have missed."
Most senior learners who are pursuing bachelor's degrees do so at UniSIM. Graduate students, meanwhile, prefer NTU, NUS and the Singapore Management University.
In recent years, NUS had a 71-year-old who completed a PhD in the arts and social sciences, while SMU had a student who completed a master's in law at the same age. The oldest student who ever enrolled at UniSIM was 86 when he graduated with a bachelor's degree in general studies a few years ago.
The largest number of learners who are 50 or older are enrolled at UniSIM. The university offers them a discount of up to 20 per cent for some of its courses, including the Bachelor of General Studies and its Continuing Education and Training (CET) programmes.
UniSIM president Cheong Hee Kiat tells The Sunday Times that there has been an increasing trend in recent years of seniors returning to school. "Learning keeps the mind engaged and helps harness interests they could not satisfy earlier," says Professor Cheong, who sits on the government-appointed Lifelong Learning Council.
However, Singapore universities have some way to go to catch up with institutions of higher learning in places such as the United States, Japan and Hong Kong.
In the US, for instance, community colleges offer a variety of courses targeted specifically at seniors for a low fee or free of charge. "The men like to do history - many are veterans and have witnessed history being played out," says Prof Cheong, who visited one such college in New York. Women prefer courses like counselling, gerontology and teaching.
There are more than 1,000 university programmes designed for seniors in the US. Many are short courses and seniors need not sit exams. "In Singapore, we need to find ways to build more learning communities for seniors that cater specifically to their needs and interests," he says.
From its early years, UniSIM has been promoting its shorter CET courses as an attractive, viable way for seniors to learn. These give many seniors who did not go to university the chance to keep learning, accumulate credits and perhaps one day fulfil a long-cherished dream.
Ms Elaine Tan, 64, fits the bill. Like many in her generation, the daughter of a small-time businessman began working straight out of school and now works as a finance manager in a small architecture and interior design firm.
Supported by her boss, she began taking short courses in finance and accounting at UniSIM in early 2013 and has accumulated enough credits for a bachelor's degree, which she hopes to pursue next year.
"I find studying a meaningful way to use my time after work," says Ms Tan, who is single. "I want to study and work for as long as I can."