A dictionary of Proverbs (Oxford Paperback Reference)

The BREAD never falls but on its buttered side
A formulation of Murphy’s Law; cf. if ANYTHING can go wrong, it will.

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  1867 A. D. RICHARDSON Beyond Mississippi iii. His bread never fell on the buttered side. 1891 J. L. KIPLING Beast & Man x. We express the completeness of ill- luck by saying, ‘The bread never falls but on its buttered side.’ 1980 Guardian 3 Dec. 12 Murphy’s (or Sod’s) Law. .. Murphy’s many relatives always quote it as ‘Buttered bread falls buttered side down—and if it’s a sandwich it falls open.’ ■luck; misfortune
  

bread see also HALF a loaf is better than no bread; MAN cannot live by bread alone.
break see (noun) never give a SUCKER an even break; (verb) HARD words break no bones; if it were not for HOPE, the heart would break; it is the LAST straw that breaks the camel’s back; OBEY orders, if you break owners; STICKS and stones may break my bones, but words will never hurt me; also BREAKING, BROKEN.
breakfast see HOPE is a good breakfast but a bad supper; SING before breakfast, cry before night.
breaking see IGNORANCE of the law is no excuse for breaking it; you cannot make an OMELETTE without breaking eggs.
What’s BRED in the bone will come out in the flesh
Lifelong habits or inherited characteristics cannot be concealed (cf. BLOOD will tell). The form and emphasis of the proverb have been altered in recent years by the omission of a negative. Cf. medieval L. osse radicatum raro de carne recedit, that which is rooted in the bone rarely comes out from the flesh.

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  с 1470 MALORY Morte d’Arthur (1947) I. 550 Sir Launcelot smyled and seyde, Harde hit ys to take oute off the fleysshe that ys bredde in the bone. 1546 J. HEYWOOD Dialogue of Proverbs II. viii. K2 This prouerbe prophecied many yeres agone, It will not out of the fleshe, thats bred in the bone. 1603 J. FLORIO tr. Montaigne’s Essays III. xiii. They are effects of custome and vse: and what is bred in the bone will never out of the flesh. 1832 J. P. KENNEDY Swallow Barn III. v. What is bred in the bone—you know the proverb. a 1957 L. I. WILDER First Four Years (1971) iv. We’ll always be farmers, for what is bred in the bone will come out in the flesh. 1981 B. HEALEY Last Ferry iv. There’s bad blood there. .. What’s bred in the bone comes out in the flesh. ■family; habit; human nature