Really? Modern psychology says we can pay attention to about seven things at once. "The magic number seven plus or minus two."
Never mind, just being a contrarian.
Couldn't agree with you more, Pacman. Practice means devoting "all" your senses and talents in an effort to improve them all. They all grow at once, don't they?
That's another thing modern science tells us, that a butterfly flapping its wings in the Himalayas can trigger a tropical storm in the Gulf of Mexico.
In other words, there's "dedicated practice" and then there's "goofing around". But goofing around isn't necessarily a bad thing. It's a good thing. It's just not "practice" in the usual sense.