LOCATION@1 was also interested in postage stamps ; on NUMBER@1 May , NUMBER@2 , the day the ORGANIZATION@1 first went on sale , he purchased several with the intent to save them , thus making him the world 's first known stamp collector .

PERSON@1 was also interested in postage stamps ; on NUMBER@1 May NUMBER@2 , the day the ORGANIZATION@1 first went on sale , he bought some to keep , thus making him the world 's first known stamp collector .
