Complex sentence: As a boy, he helped make and deliver funeral wreaths for his grandmother and aunt's florist business, during the deadly Influenza of 1918, which amount of death witnessed first-hand, left a profound mark on him at a young age.
Split into simpler sentences: As a boy, he helped make and deliver funeral wreaths for his grandmother and aunt's florist business, during the deadly Influenza of 1918, which amount of death witnessed first-hand. This left a profound mark on him at a young age.