I don’t think brains get more complex because of additional information.

Also, what I’m not sure you mean with having “enough capacity to reflect ourselves by processing everything”? Do you mean processing every time a neuron fires, and which neurons get what kind of stimulus from it? Or do you mean looking at all molecules/atoms/fundamental particles and considering their state and following reaction?

I think we should be capable of understanding the concepts that make our brains work eventually. But I don’t think we have the capacity to monitor everything another brain is doing and understand/interpret it in real time. A computer might be able to at some point, when we understand more about neurology.