HEAD: idioms [advanced]

Phrase having strong affectionate emotions with great interest in a romantic relationship
It’s good, old-fashioned fun when a poor mechanic’s son named David (Alex Pettyfer) falls head over heels in love with the rich and gorgeous Jade (Gabriella Wilde) and she — amazingly — falls just as hard for him.
Adjective has a natural ability or tolerance to do something
This 29-year-old has a head for heights and has been honing his death-defying skills since the age of five, with circus troupes around the globe.
Phrase be able to understand something
These days we're surrounded by large numbers. We're told that there are 7-billion humans on Earth, and that there are upwards of 300-billion stars in the Milky Way. Good luck trying to wrap your head around that!
Verb leave in order to start a journey
In NASA's interplanetary version of the Mayflower, space colonists would head off into the cosmos with no real anticipation of returning to the Earth.