Sometimes, a situation in one culture or part of the globe has an equivalent in another culture, but it is not identical. The United States uses miles, Europe uses kilometers. A polite greeting might be a handshake, a kiss on the cheek, or a bow. A simple dinner might be lentil stew or a frozen pizza. In Spain, the stork does not bring babies; they come from Paris. July is winter in Tierra del Fuego. To say nothing of slang, taboo words, swear words, and insults.
When you're translating, you (or your editor) must decide if you want to adapt the original text into something culturally equivalent, or if you want to retain the "foreignness" of the text? Depending on the work and what you want to do with it (is the translation for light entertainment or for scholarly use?), your answer may vary.
Consider this from Shakespeare's Sonnet XVIII:
Shall I compare thee to a summer's day?
Though art more lovely and temperate:
Rough winds do shake the darling buds of May,
and summer's lease hath all too short a date.
Here's a translation by Astrana Marín:
¿Te compararé a un día de primavera? Eres más
deleitable y apacible. La violencia de los vientos desgarra
los tiernos capullos de mayo, y el arriendo de
la primavera vence en fecha demasiado corta.
(Literally: Will I compare you to a spring day? You are more / delightful and placid. The violence of the winds tears / the tender buds of May, and the lease of / the spring gives way in date too short.)
Marín changed "summer" to "spring" because in Spain, May is considered part of spring, though in Britain, it is part of summer. She didn't want her readers stumbling over the seasonal difference.
Usually, though, "strangeness" is retained in texts these days. That doesn't mean translations come out the same. Here's the same verse translated by Manuel Mujica Lainez:
¿A un día de verano compararte?
Más hermosura y suavidad posees.
Tiembla el brote de Mayo bajo el viento
y el estío casi no dura nada.
(To a day of summer to compare you? / More beauty and gentleness you possess. / Trembles the shoot of May under the wind / and the summer almost doesn't last nothing.)
Now, by Agustín García Calvo:
¿A un día de verano habré de compararte?
Tú eres más dulce y temperado: un ramalazo
de viento los capullos de Mayo desparte
y el préstamo del estío vence a corto plazo;
(To a day of summer must I compare you? / You are more sweet and temperate: a gust / of wind the buds of May splits / and the loan of summer gives way in short term;)
Note that Mujica's poem uses ten-syllable lines and García uses fourteen. García's also rhymes. Mujica, however, maintains the sexual ambiguity of the person to whom the poem is addressed, while García makes it a male.
On the other hand, and famously, the musical My Fair Lady contains a song with the words, "The rain in Spain falls mainly on the plain." (Actually, it falls on the northern coast.) The "long a" sound is hard for a Cockney girl to make. The musical has enjoyed great success in Spain, and in the Spanish version, the words are, "La lluvia en Sevilla es una maravilla." (The rain in Seville is a marvel.) (The climate is semi-arid.) In Spanish, the "ll" sound can be hard to make.
This is a beautiful example of successful adaptation. Sometimes you must deviate from the original text to translate well.