Slang is arguably the most alive form of language - it has a vividness and an energy that is often lacking in more formal speech. Think, for a moment, about the phrase "wake up and smell the coffee" -
Notice that the phrase describes what language does - it doesn't describe what your senses do. What I mean is, reading the phrase "smell the coffee" wakes up the appropriate centres in your brain, and allows you to choose to intensify your attention on the smell of freshly brewed coffee. This is the opposite of what happens in life - it is the smell of the coffee that causes us to wake up.
Notice that someone else has made you coffee - or that you set the coffee maker to automatic - so that you will wake up pleasantly at precisely the right time.
Notice that smelling the coffee is a nice way to wake up - it's much better than the cat/dog yowling and jumping or the alarm crashing into your lovely morning dreams.
Notice that if you want someone else to wake up, you have the option of simply putting the coffee on and waiting for what they want to get them out of bed and bring them into your space.