answer: Doctor Richardson tells #Person1# when he began to have the idea of helping aids patients. What caused his great change was that his interest in lab work made him get a PhD and then began research on medicine.
documents: #Person1#: Doctor Richardson. When did you began to have the idea of helping aids patients?
  #Person2#: Frankly speaking, I didn't have any sort of idea of what I would do at all when I left high school at the age of 16. Then I found a simple job in a small medical lab. Back then I never dreamed that one day I would help discover a medison that would save thousands of lives.
  #Person1#: Then what caused your great change?
  #Person2#: I loved lab work, so I went back to school at night and worked at the lab during the day. After 12 years, I had my PhD, then I went to work at a medical company where I began research on a medicine to treat aids patients. For me a drug saves more than life. It can save a family.
  #Person1#: I couldn't agree with you more there.