aback, abruptly, accidentally, bang, by accident, by surprise, dash, guiltlessly, hastily, ignorantly, impetuously, implausibly, improbably, impulsively, inadvertently, innocently, insensibly, like a flash, like a thunderbolt, mistakenly, of a sudden, off base, on short notice, plop, plump, plunk, pop, precipitantly, precipitately, precipitously, sharp, short, slap, smack, startlingly, sudden, suddenly, surprisingly, unanticipatedly, unaware, unconsciously, unexpectedly, unforeseeably, unguiltily, unintentionally, unknowingly, unmindfully, unpredictably, unprepared, unready, unsuspectingly, unwittingly, without notice, without warning, witlessly
ignorance, nescience, tabula rasa, crass ignorance, ignorance crasse, unfamiliarity, unacquaintance, unconsciousness, darkness, blindness, incomprehension, inexperience, simplicity, unknown quantities, x, y, z, sealed book, terra incognita, virgin soil, unexplored ground, dark ages, smattering, sciolism, glimmering, dilettantism, bewilderment, incapacity, pedantry, charlatanry, charlatism, Philister, Philistine, ignorant, nescient, unknowing, unaware, unacquainted, unapprised, unapprized, unwitting, unweeting, unconscious, witless, weetless, a stranger to, unconversant, uninformed, uncultivated, unversed, uninstructed, untaught, uninitiated, untutored, unschooled, misguided, unenlightened, Philistine, behind the age, shallow, superficial, green, rude, empty, half-learned, illiterate, unread, uninformed, uneducated, unlearned, unlettered, unbookish, empty-headed, dizzy, wooly-headed, pedantic, in the dark, benighted, belated, blinded, blindfolded, hoodwinked, misinformed, au bout de son latin, at the end of his tether, at fault, at sea, caught tripping, unknown, unapprehended, unexplained, unascertained, uninvestigated, unexplored, unheard of, not perceived, concealed, novel, ignorantly, unawares
, for anything, for aught one knows, not that one knows, Int, God knows, Heaven knows, the Lord knows, who knows, nobody knows, ignorance never settles a question, quantum animis erroris inest!, small Latin and less Greek, that unlettered small-knowing soul, there is no darkness but ignorance.
inexpectation, non-expectation, false expectation, miscalculation, surprise, sudden burst, thunderclap, blow, shock, start, bolt out of the blue, wonder, eye opener, unpleasant surprise, pleasant surprise, nonexpectant, surprised, unwarned, unaware, off one's guard, inattentive, unexpected, unanticipated, unpredicted, unlooked for, unforeseen, unhoped for, dropped from the clouds, beyond expectation, contrary to expectation, against expectation, against all expectation, out of one's reckoning, unheard of, startling, surprising, sudden, unpredictable, unforeseeable (unknowable), abruptly, unexpectedly, surprisingly, plump, pop, a l'improviste, unawares
, without notice, without warning, without a 'by your leave', like a thief in the night, like a thunderbolt, in an unguarded moment, suddenly, Int, heydey!, little did one think, little did one expect, nobody would ever suppose, nobody would ever think, nobody would ever expect, who would have thought? it beats the Dutch.