1. Learn where the phrase "labor of love" comes from.
http://www.phrases.org.uk/meanings/222400.html
2. Learn where the phrase "by the skin of your teeth" comes from.
http://www.phrases.org.uk/meanings/83000.html
3. Learn where the phrase "straight and narrow" comes from.
http://www.phrases.org.uk/meanings/strait-and-narrow.html
4. Learn where the phrase "apple of my eye" comes from.