expression
now that you say that; now that you mention it
Fixed expression used when someone's remark makes you realize something you hadn't noticed before. Often followed by a statement of that realization.
言われてみれば、確かに彼は最近元気がない。
Now that you mention it, he really has seemed down lately.
言われてみれば、その映画は見たことがない。
Now that you say that, I realize I've never seen that movie.