You should first define what actually means "understanding the brain" before you try to answer this question.
Does "understanding of the brain" mean, that we can construct or simulate a brain? An artificial brain, which reproduce our intelligence and consciousness?
There is no reason to believe, that we can't do this.
A brain is part of our world, governed by physics.
However, we will never be able to understand the thought process down to each individual activation of the neuron.
That's like trying to "understand" and follow the movement of each atom in my coffee next to me.
Does "understanding of the brain" mean, that we can construct or simulate a brain? An artificial brain, which reproduce our intelligence and consciousness?
There is no reason to believe, that we can't do this. A brain is part of our world, governed by physics.
However, we will never be able to understand the thought process down to each individual activation of the neuron.
That's like trying to "understand" and follow the movement of each atom in my coffee next to me.