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I came across this phrase on the website: http://www.bspcn.com/about/
Over all, this site is sure to be appreciated by anyone that needs to take his or her mind off of more pressing matters.
I looked it up into the dictionary, and the explanation for take his mind off is "if an activity takes someone's mind off their problems, it stops them from thinking about it".
But why does of exist in the sentence above?