Ever watched an educational video and wished you could ask a question? Imagine a simple button that could instantly clarify confusing concepts. Researchers are exploring exactly that with the innovative "Huh?" button—a tool that leverages the power of Large Language Models (LLMs) to enhance learning from online videos. The idea is elegantly simple: when a viewer encounters a difficult concept, they click the "Huh?" button. The video pauses, and the LLM, using the video's transcript, generates a clear, concise explanation of the challenging segment. Need more detail? Clicking again provides a simplified and expanded explanation. This approach combines the low-effort interactivity of digital learning with the personalized clarification of a face-to-face tutor. A proof-of-concept experiment demonstrates the feasibility of this approach, successfully clarifying concepts in videos ranging from computer science to economics and biology. The researchers even built a prototype integrated with YouTube, showing how this technology could be readily deployed. Notably, this LLM application is highly cacheable, as the explanations for a given timestamp remain the same for all users. This drastically reduces the energy consumption and environmental impact typically associated with LLMs. While still in its early stages, the "Huh?" button represents a compelling example of how AI can personalize and enhance the online learning experience. Future research will focus on rigorously evaluating the effectiveness of these AI-generated explanations and exploring even more efficient ways to leverage LLM power while minimizing its environmental footprint.