The human brain is undoubtedly the most complex natural object yet encountered in the universe, and we still know very little about it. It's entirely possible that the functioning of the human brain is beyond the comprehension of the human brain.
I took a free, Ed-X course back in 2013 on Neurology 101 and was amazed at the intricate level of detail and sophistication in just a single neuron. How the network of millions of neurons in the brain behaves is simply staggering to consider, but think about this - each neuron in your head can be connected to any one or more of the millions of other neurons, and the mathematically possible number of different configurations is greater than the number of atoms in the known universe.
Let me put it this way - if the mind isn't exactly infinite, it's far greater than anything you can ever know.