Explore a comprehensive commentary on Andrej Karpathy's influential 2015 article "The Unreasonable Effectiveness of Recurrent Neural Networks." Delve into the groundbreaking developments in sequence-to-sequence models that paved the way for modern NLP advancements like GPT-3. Learn about character-level language models, various RNN types, and their applications. Examine prediction and activation visualizations, neuron behavior, and subsequent related work in the field. Gain insights into how this article helped shape the tech community's understanding of machine learning's potential in handling text data.