Zhao Yi held the opposite view.
He didn't think that biological research or medical research was just a hobby. Rather, for him, mathematics was the hobby.
A hobby is the interests and abilities that diverge from one's main profession.
Biology is his chosen major. He decided to study biology courses and knowledge and pursue a career in biological research.
So, to him, studying and researching biology is life, is work. Research on mathematics or other areas could only be considered hobbies.
The reason he could make achievements in mathematics in a short time even international accomplishments, is due to the nature of the subject--
Research in pure mathematics and number theory can be solitarily conducted in a room, where problems can be solved merely by careful thought.
It is different with biology.