No, neurons firing in ones brain “enables you to be aware of the source of your thoughts” which is your brain and it is not ‘simpler than any thought’. Any thought is just, at its most basic, a certain pattern of neuron firings in ones brain and ones brain contains all possible patterns or thoughts it could have at that time. So the brain is not itself a thought, is the source of ones thoughts, is researchable and specifically more complex then any given thought.
Neurons firing in ones brain, is the result of the interaction between the complex and the simple, where each neuron is local w.r.t what you call brain, and brain is non-local w.r.t what you can neuron.
If your brain is aware of itself as a the source of its thoughts, this awareness is not itself a thought, and this level is not researchable because it is simpler than any thought (you cannot get it by thinking about it).
Neuron, Brian, Local, Non-local, Definition, Relation, Element, Complex, Simple or any other agreed concepts are all represented at the level of thoughts, but I am talking about self-awareness, which is not itself a thought.
You don't get it because you are not aware of yourself without thoughts (yet).
The complexity of man's brain enables him to be aware of himself without thoughts, and you do not get that level because your awareness is not trained to get itself at the level of the source of its thoughts (yet), which is not a thought because it is simpler than any thought.
Again, people along history that got it, described it (where any description or thought about it, is not it) as simultaneously the most intimate (local) experience AND the most non-personal (non-local) experience, and this is exactly REI.