As packet networks become extremely large, as their applications and end users become more diverse and extremely numerous, a design based on a single view of how a network should operate becomes harder to justify. Thus each part of the network should be aware of its environment, of its users, of its resources, of its performance, of the energy it is consuming and of the threats that it is facing, and should use this awareness as an operational means to adapt its behaviour accordingly. This tutorial paper sets the stage for these ideas, and shows a simple and practical way forward based one the Cognitive Packet Network routing algorithm and the notion of Self-Aware Networks.