What is the meaning of this figure of speech knocked me over with a feather.?

The phrase "knocked me over with a feather" is an idiomatic expression that conveys being unexpectedly surprised or astonished by something. It implies that the shock or impact of the news or event was so profound that it felt as light as a feather, yet it had a strong effect on the person. This figure of speech emphasizes the contrast between the lightness of a feather and the intensity of the surprise experienced.