An expression used to acknowledge that, upon hearing someone's remark, you realize it might be true; 'now that you mention it.'
言われてみれば、彼の言うことには一理あるね。
Now that you mention it, there's some truth to what he says.
言われてみれば、このシャツは色が合っていないかも。
Now that you say that, this shirt might not match.
あの時のサイン、言われてみれば怪しかったね。
Thinking back, now that you mention it, that sign was suspicious.