I was searching for some old books containing many of my favourite Chinese poems.
My books and my room at my parents' house have seen extensive changes since I moved to live with my brother Lee Hsien Loong's family from 2002 to 2005. My room at Hsien Loong's house was too small to move more than a tenth of the books I needed. So the rest, I left in my room in Oxley Road.
In 2003, after my mother suffered a bleed into her brain, my room at my parents' house was extensively renovated so a nurse could rest there. The nurse needed more creature comforts than I did. So a bed was placed in the room and a water heater was installed in the bathroom so she could have a warm shower.
And my books, packed in boxes, were moved into the basement. It took me two days a few weekends ago to find the books I wanted and even then, I couldn't find several.
But by chance, I did find the nine medals that I had been awarded for topping my cohort in medical school as well as individual prizes in subjects where I was first in class. One medal that I recall was made of pure gold was missing. I had handed it to my mother to be locked up as I have a talent for losing things.
I was surprised that I felt no sense of triumph or joy when I found the medals. In my immature youth, I had worked very hard to earn them. Indeed, 35 years ago when I was in medical school, I would study the following year's subjects even while on vacations, reading several textbooks on each subject before the new term began.
Hence, I knew not only the scientific facts that the authorities agreed about, but I was also aware of what was still controversial. When term started and I attended the lectures, I didn't have to take notes except when I wanted to prevent myself from falling asleep.
I remember that while I was still a medical student, I accompanied my parents on a trip to Osaka. A Mr S. Oya, an elderly gentleman who owned Teijin, a manufacturer of synthetic fibre, invited us to his house for dinner. His first wife had died and he had married a woman much younger than he was - a vivacious Japanese lady not at all sedate as one would expect a Japanese wife to be. When my parents introduced me to her, she prophesied 'one day you will be a famous professor'. I did not demur since that indeed was my ambition.
Decades have passed since then, and my priorities in life have changed. Medals and titles now mean little to me. What matters is that I must do right, and I should do so even if I offend people who have power over me.
I have acquired the title of 'Professor', but that gives me no joy. In fact, I prefer to be addressed as 'Dr'. The title 'professor' has been sprinkled around liberally among the medical fraternity here, and there are some professors with whom I certainly do not wish to be grouped.My younger brother, Lee Hsien Yang, once asked me: 'Why do you step on powerful and sensitive toes?'
I replied: 'But if I don't, who will do so to put things right?'
Hsien Yang is no coward. When in the army, to which he was bonded for eight years for accepting the President's Scholarship as well as the Singapore Armed Forces Scholarship, he earned badges for scuba diving as well as parachuting. He needed to get only one of the two badges, as all senior officers had to to prove to their men that they were not cowards.
Hsien Yang got both. Like me, he likes physical challenges. But as a businessman, he knows that antagonising powerful people does not make good business sense.
But I am not a businesswoman; I am a doctor serving patients in the public sector. Since 2008, I have also been a regular columnist in The Straits Times and The Sunday Times. I am much less important and well known than my two brothers or my sisters-in-law. But writing columns gives me a chance to discuss social trends and to point out government policies that I think are wrong.
That does not mean my bosses cannot take action against me if they so wish. But it is better to do what is morally correct than to be so afraid that one does not dare say 'boo' to our superiors. Pay rise, bonus, promotion or demotion are much less important than doing what is right. Besides, if I do not try to right a wrong that I am aware of, my conscience will bother me.
I don't think my temperament has changed since I was a child, but my purpose in life certainly has - and I hope it has changed for the better. I try not to hesitate to speak up when my superiors or even the Government do something that I think is not in the best interest of Singapore. The criticism is made with the sincere wish to improve our system and to benefit Singaporeans.
I do all this not because I wish to score points or gain glory. I do so because I owe Singapore a debt for the opportunities it has given me. In return, people in my position should always do what they think is the best for Singapore.

1. Prof Khoo Tsai Kee.