Neural responses in the mammalian cerebral cortex are notoriously noisy – varying dramatically on a trial-to-trial basis. This apparent noisiness of neural responses has two possible sources. Either the brain is inherently noisy, or our understanding of the brain is dramatically incomplete (e.g. our ignorance is much larger than our knowledge). Recent investigations in behaving mice have revealed that a significant fraction of cortical activity relates to rapid, ongoing variations in behavioral and brain state, from changes in arousal to overt and covert movements of the face and body. Taking these rapid variations in state into account reveals a much more precise and reliable brain than previously appreciated. Another key role of the brain, and particularly the cerebral cortex, is to interweave the past (memory), with present perceptions, and future goals. The massive interconnectivity of the cerebral cortex allows for context dependent behavior through rapid gain modulation – variations in neuronal responsiveness through changes in ongoing barrages of synaptic activity. We hypothesize that rapid gain modulation allows the cerebral cortex to operate as a functional connectivity machine – providing for the interaction of cortical neurons and networks in a contextually dependent manner. It is an exciting time in neuroscience – we are coming closer and closer to providing a detailed mechanistic understanding of spontaneous and evoked neural activity, from the biophysical properties of neurons, to the operation of local and large scale networks, to the neuromodulation of behavior and state.