Japanese scientist Kenso Soai, one of two winners of Wednesday’s Nobel Prize in Chemistry, knew the significance of his research all along — though he had not expected that he would ever get the coveted prize, let alone this year.

When he received a phone call from the Nobel Foundation in Sweden notifying him of the prize a few hours before the announcement, he was out shopping for groceries at a supermarket near his home in Shiki, Saitama Prefecture.

“I may sound arrogant, but I had thought I would not get complaints if I won,” Soai, 76, told a news conference on Wednesday night at the Tokyo University of Science, where he taught and researched until he retired in 2016.