'It slipped my mind', why not say 'It slipped from my mind'?

[Iwanna]

Is the preposition "from" necessary here or not? why?

[lost_soul]

Well, the usual collocation is to slip somebody's memory/mind. You cannot add "from" to this - it would sound weird, I guess.
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Alex

A native speaker of Russian

[Yankee]

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"It slipped my mind" is the standard, idiomatic wording.
The word 'from' is neither necessary nor is it used in this expression.

(Look at definition #56 here.)
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Amy
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ESL teacher, translator, and a native speaker of American English

[Iwanna]

many thanks