Addiction

[T]he addict himself has a special blind spot as far as the progress of his habit is concerned. He generally does not realize that he is getting a habit at all. He says there is no need to get a habit if you are careful and observe a few rules like shooting every other day. Actually, he does not observe these rules, but every extra shot is regarded as exceptional.

William S. Burroughs, Junky, Harmondsworth, Middlesex, England ; New York, N.Y., U.S.A, 1977, p. 22