We can’t input and output at the same time.
Computers can because they have separate processors.
Humans do not. And whatever your 5th-grade science teacher said about left and right brains is almost complete nonsense.
It’s difficult to output without some experience or information we can process and change into something new—some material we can use to create. Input.
Interesting creative output requires interesting creative input.
But the output directs the input.
Without our own output to direct what we put in, we just become someone else’s input.