“Perhaps it's rude to notice when a wizard does something strange.”

Source: Saving Francesca

Bangkok Haunts, Ch. 22.

Source: The Goose Girl

Source: She Is the Darkness (1997), Chapter 41 (p. 412)

Letter to his brother, A.P. Chekhov (October 13, 1888)
Letters

Source: City of Bones

Source: Every Day

Characters, Ch. 1 : Thoughts About People
Sketches by Boz (1836-1837)
Context: It is strange with how little notice, good, bad, or indifferent, a man may live and die in London. He awakens no sympathy in the breast of any single person; his existence is a matter of interest to no one save himself; he cannot be said to be forgotten when he dies, for no one remembered him when he was alive. There is a numerous class of people in this great metropolis who seem not to possess a single friend, and whom nobody appears to care for. Urged by imperative necessity in the first instance, they have resorted to London in search of employment, and the means of subsistence. It is hard, we know, to break the ties which bind us to our homes and friends, and harder still to efface the thousand recollections of happy days and old times, which have been slumbering in our bosoms for years, and only rush upon the mind, to bring before it associations connected with the friends we have left, the scenes we have beheld too probably for the last time, and the hopes we once cherished, but may entertain no more. These men, however, happily for themselves, have long forgotten such thoughts. Old country friends have died or emigrated; former correspondents have become lost, like themselves, in the crowd and turmoil of some busy city; and they have gradually settled down into mere passive creatures of habit and endurance.

Attributed to Strauss at many sites on the internet, this is actually Norman Maclean, in A River Runs Through It (1976)
Misattributed