Can we live in the Now constantly?

Integrating Martin Buber's "I and Thou" with Iain McGilchrist's "The Master and His Emissary", I come to the conclusion that we cannot constantly live in the Now. To do so would revert the insight that Iain McGilchrist has when he says that living from our left hemisphere all the time, we would be well fed but become somebody else's lunch in the meanwhile.

To constantly live in the Now, according to the differentiation of the "I-Thou" and the "I-It", would mean that we are in a constant flow state with everything, in dialogue with "You", but starving and incapable to navigate the world.

What do you think?

Martin Buber (translated from German):

It is impossible to live in the mere present; it would consume you if you did not take care to overcome it quickly and thoroughly. But it is possible to live in the mere past; indeed, it is only in the past that a life can be established. One need only fill each moment with experience and use, and it no longer burns.

And in all seriousness, truth, you: without It, man cannot live. But those who live with It alone are not human.