Excision of errors and confusion about quantum mechanics -- and stimulation of thoughtful and adventurous readers are pre-eminent rationales of this entire work; these requiring definitions and analysis of underlying concepts of quantum mechanics, of quantum field theory -- why probability is given by the absolute square, what wavefunctions are and are not and why, and many others -- and also examination of some from the philosophy of science. People''s beliefs about quantum mechanics are often just the reverse of what fundamental principles give, seen most spectacularly with the EPR ''paradox''. The puzzles, the mystical, the bizarre, come merely from negligence, from blunders, including the outlandish belief that the universe must be explained using classical physics. Careless, unthinking physicists, and gullible journalists who naively accept their confusion as statements about nature, cause so much misunderstanding and nonsense about physics. Among the many examples considered are the non-existence in quantum mechanics of waves and particles, so of wave-particle duality; the reason that general relativity must be the quantum theory of gravity; the mystery of the cosmological constant: why people believe in it though it would be obvious to a high school student that there cannot be any, it must be zero; the absurdity (and wild incorrectness) of much of the discussion about the vacuum; the required locality of quantum mechanics and the impossibility of action-at-a-distance; and many others. Many blunders, not only about physics, come from abuse of language, the use of words, phrases, sentences without content, with con- notation but no denotation, of names --- quantum mechanics, particles, waves, and so on -- that deceive and misrepresent, of questions that ask nothing. It is not only in physics that answers to questions without meaning smother and hide.