Auto detection of missing attachments

Very interesting feature from GMAIL now. I was sending a mail with an attachment. After writing down the mail, i clicked the send button without attaching the intended attachment. I was surprised to see a pop-up message from Gmail as seen below.
It says "did you mean attach files", you wrote "find the attached in your message", but there are no files attached"?
Isn't this awesome? Anyhow, one thing is to check are they scanning our emails before sending? howz it working? You do believe innovations making life easier? You can try this, you'll come to know