Horacio Herrera shares his positive experience with pair programming alongside the Gatsby team, highlighting its benefits in learning and contributing to open-source projects. Initially apprehensive due to his limited experience with Gatsby, Herrera found the session with Jason Lengstorf to be immensely valuable, as it boosted his confidence and led to his first contribution to the project. He appreciated the collaborative dynamic where both participants were actively engaged, and he was particularly surprised by Lengstorf's willingness to assist a stranger. Herrera enthusiastically recommends pair programming, especially for those new to the practice, emphasizing its value beyond just coding to include learning and development with an expert.