How to Explain control emotions during period to a Five-Year-Old

http://jeffreyhmqf809.tearosediner.net/15-terms-everyone-in-the-control-over-emotions-industry-should-know

It's said ,"Emotions control actions and it's a basic law of nature". But what does this law mean to youpersonally? You control feelings and can learn to consciously use your actions to be controlled by these.