An article in the current New York Review of Books includes an article by Christopher Benfey entitled "Pain and Parentheses" which quotes someone named Geoff Dyer as claiming that "the most famous parenthesis in postwar literature" was in fact penned by our own VN:
My very photogenic mother died in a freak accident (picnic, lightning) when I was three, and, save for a pocket of warmth in the darkest past, nothing of her subsists within the hollows and dells of memory.
Whether or not this is true, I have no idea. You may pursue other parenthetical examples at http://www.nybooks.com/blogs/nyrblog/2014/apr/26/pain-and-parentheses/
Carolyn