What is the connection between the fragrance and simplicity of osmanthus and the old janitor?

In the article, the fragrance of osmanthus fragrans can be pleasant, but it is not unassuming, simple and implicit; The old man sacrificed his rest time, silently waited for the eager author to come home late, never urged the author to leave, selflessly helped others without expecting anything in return, and silently dedicated himself without expecting anything. In the author's eyes, this is similar to the implicit simplicity of osmanthus. Therefore, under the guise of osmanthus, the author praised the noble quality of people like grandpa, opening doors for others without asking for anything in return.