Cell biologist Yoshinori Ohsumi was a late bloomer and already 43 when he began research in the field in which he would eventually be honoured with a Nobel Prize.
Dr Ohsumi, now 71 and whose signature mane of white hair and beard is perhaps his most defining feature, won the Nobel Prize in physiology or medicine last Monday. It was for his work in autophagy that could lead to breakthroughs in treatments for cancer, Parkinson's disease and Alzheimer's disease.
The term "autophagy" is derived from the Greek words meaning "self-eating". It refers to the internal recycling system by which cells break down unnecessary or damaged proteins and molecules into their component parts and then rebuild them into new structures.
It was in 1988, after he started a one-man laboratory at the University of Tokyo, that Dr Ohsumi observed this process in yeast in what was supposedly "unfashionable" research.
"I don't feel comfortable competing with many people and instead I find it more enjoyable doing something nobody else is doing," Dr Ohsumi, now an honorary professor at the Tokyo Institute of Technology, said last week.
FAR FROM DONE
I have yet to fully understand the mechanism. The cells in living organisms are full of amazing functions and we have yet to fully elucidate the functions of baker's yeast. There is still huge room for further study in this area.
DR YOSHINORI OHSUMI, now an honorary professor at the Tokyo Institute of Technology, has devoted 271/2 years to his research.
"In a way, that's what science is all about and the joy of finding something inspires me."
But he had floundered in his path towards being a pioneer in autophagic research. He studied chemistry as an undergraduate, but did not find it attractive because it was "already quite established".
He then studied protein synthesis as a graduate student, but "did not get very good results".
Though he graduated with a doctorate in molecular biology from the University of Tokyo in 1974, he "discovered it was very difficult to find a good position in Japan".
He then moved to New York, where he took on a post-doctoral position at The Rockefeller University. "That was the hardest time in my life," he said in a 2012 interview with the Journal Of Cell Biology.
"I was supposed to establish a system for in-vitro fertilisation in mice, but I did not know very much about early embryology and I had only a very small number of eggs to work with. I grew very frustrated."
He would later join another researcher who was studying DNA duplication in yeast - which was Dr Ohsumi's first introduction to the organism and would be instrumental in his discovery of autophagy.
It is when the internal autophagic process goes awry that intractable medical conditions start to occur: Too much of it leads to more cancerous cells, while too little leads to issues related to ageing.
The Nobel Assembly said in announcing its decision: "Thanks to Ohsumi and others following in his footsteps, we now know that autophagy controls important physiological functions where cellular components need to be degraded and recycled."
Japanese Prime Minister Shinzo Abe, congratulating Dr Ohsumi for the win, said last week that his work "has brought light to people struggling with intractable diseases".
Despite devoting 271/2 years to the research, Dr Ohsumi is far from done. He said: "I have yet to fully understand the mechanism. The cells in living organisms are full of amazing functions and we have yet to fully elucidate the functions of baker's yeast. There is still huge room for further study in this area."
Ever since he was a young boy, the Fukuoka native knew that he wanted to work in science.
He said at a press conference last week: "I was hopeless in sports and had no talent in art. By the process of elimination, I've thought since I was a child that it would be most suitable for me to become a scientist."
Of the beard he started growing in his 20s, because he was boyish- looking and wanted to be taken seriously, he said: "It's gradually become totally white."
Dr Ohsumi, who is married with two children, has said he is concerned about the future of Japan's scientists.
"Unfortunately, these days, at least in Japan, young scientists want to get a stable job and so they are afraid to take risks," he said in the 2012 interview.
"Most people decide to work on the most popular field because they think that is the easiest way to get a paper published."
While urging more government support to groom the next generation of researchers, Dr Ohsumi also had a message for young scientists last week.
"I'd like to tell young people that not all can be successful in science, but it's important to rise to the challenge," he said.