In his 2013 TEDx Talk, "The first 20 hours," author and business expert Josh Kaufman busts the myth that learning new skills takes a lot of time.
Proficiency, Kaufman says, is really only 20 hours away.
Here are just a sample of the many you could pick from.
Learn to play a song on a musical instrument
Music theory is highly complex, but a week should be enough time to learn a single song on the ukulele or harmonica.
(At the end of his TEDx Talk, Kaufman shows off his ability to play a few chords in a medley of pop songs on his own ukulele, which he spent just 20 hours practicing on.)
On Quora, Karan Babar suggests picking a somewhat rare instrument if you want to impress people most.
Learn to drive stick shift
simpologist | Flickr
Automatic transmissions are no doubt easier, but the ability to shift gears while driving still turns some heads. It's also a useful skill to have if you ever need to drive someone else's car.
The actual mechanics of using the clutch and gear shift are straightforward, but you'll probably spend most of your week learning how to time your shifts correctly. Nobody likes to lurch.
Learn to solve a Rubik's cube
Speed-cubers — the people who solve Rubik's cubes as fast as possible, sometimes in less than 10 seconds — will tell you there's nothing all that special about the puzzle.
You just need to know a set of algorithms — or turn patterns — that orient pieces of the cube one at a time. Memorizing the order of those turns can be done surprisingly quickly.
A beginner could easily solve a Rubik's cube in less than two minutes over the course of a week.