From Longman Dictionary of Contemporary English(now I) come to think of it(now I) come to think of itADDused to mention something you have just realized or remembered ‘Were there any letters for me?’ ‘Yes there were, come to think of it.’ → think
Examples from the Corpus
(now I) come to think of it• So did Mom, come to think of it.• You never know, come to think of it.• Come to think of it, Columbia wouldn't have been around if it hadn't been for the blues.• Come to think of it, even Hillary Rodham Clinton could learn something from Alexander about how to invest her money.• Come to think of it, he'd seemed rather a decent chap, some one it might be worth getting to know.• But now that she came to think of it she had never been out to any sort of meal with John.• Come to think of it, they might want to hang on to those packing crates. 