A dictionary of Proverbs (Oxford Paperback Reference)

A MISS is as good as a mile
The syntax of the proverb has been distorted by abridgement: the original structure is apparent from quot. 1614.

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  1614 W. CAMDEN Remains concerning Britain (ed. 2) 303 An ynche in a misse is as good as an ell [a former measure of length equal to about 1.1 m]. 1655 T. FULLER Hist. Cambridge 37 An hairs breadth fixed by a divine-finger, shall prove as effec-tuall a separation from danger as a miles distance. 1788 American Museum Apr. 382 A miss is as good as a mile. 1825 SCOTT Journal 3 Dec. (1939) 28 He was very near being a poet— but a miss is as good as a mile, and he always fell short of the mark. 1978 T. SHARPE
  

Throwback vii. If you aimed at a grouse it was hit or miss and a miss was as good as a mile. "error
You never MISS the water till the well runs dry

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  a 1628 J. CARMICHAELL Proverbs in Scots no. 1140 Manie wats [know] not quhairof [whereof] the wel sauris [tastes] quhill [until] it fall drie. 1659 J. HOWELL Proverbs (British) 24 Of the Well we see no want, till either dry, or Water skant. 1721 J. KELLY Scottish Proverbs 351 We’ll never know the worth of Water ‘till the well go dry. 1874 H. LINN You never miss Water 5 Do not let your chances, like sunbeams pass you by; For you never miss the water till the well runs dry. 1996 Washington Times 18 July A6 ‘There is an old adage,’ Sen. Robert Byrd.. recalled this week, ‘that “you never miss the water until the well runs dry.”’ "blessings; gratitude and ingratitude
  

miss see also what you’ve never HAD you never miss; a SLICE off a cut loaf isn’t missed.
If you don’t make MISTAKES you don’t make anything

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  1896 CONRAD Outcast of Islands III. ii. It’s only those who do nothing that make no mistakes, I suppose. 1925 Times 9 Nov. 17 The comforting assurance that ‘a man who never makes mistakes never makes anything.’ 1980 M. DRABBLE Middle Ground 86 If you don’t make mistakes you don’t make anything, she said, a motto which Hugo seemed to remember having seen pinned over the desk. "error; risk