Similar to the unexpected always happens.
There is a proverb that ‘nothing is certain but the unforeseen,’ and in fact few things turn out as we expect them.
[1886 J. A. Froude Oceana vii.]
There is nothing certain to happen, says the proverb, but the unforeseen. Tomorrow will have its cares.
[1905 A. Maclaren Gospel according to St. Matthew I. 322]
Related to: certainty and uncertainty; foresight and hindsight
Bibliography of major proverb collections and works cited from modern editions is available here.
