In 1906 he discovered the structural formula of atoxyl, a chemical compound that had been shown to be able to treat sleeping sickness (Silesia). Following this discovery, he tried to create a less toxic version of the medicament. In 1909 he and his student Sahachiro Hata developed Salvarsan, a treatment effective against syphilis. This work was of epochal importance, stimulating research that led to the development of sulfa drugs, penicillin and other antibiotics ("Paul R. Ehrlich").
He coined the term "chemotherapy" and popularized the concept of a "magic bullet" ("Paul R. Ehrlich"). He is credited with the first empirical observation of the blood-brain barrier and the development of the first antibiotic drug in modern medicine (Silesia).
How does this affect me?
Erhlich developed the first antibiotic drug in modern medicine. Without this contribution, the various antibiotic drugs used today probably would not exist. Ehrlich definitely has helped society since then because he began the revolution of antibiotic drugs.
(image from http://www.probertencyclopaedia.com/j/Paul%20Ehrlich.jpg)