This study employs thematic analysis to delve into the experiences of 12 alumni engineering students who participated in the elective course "Collective Creation: Improvised Arts and Engineering" at the Swiss Federal Institute of Technology of Lausanne (EPFL) since 2017. Focusing on the lasting impressions left on alumni, the research investigates retained knowledge and skills, their impact on educational journeys, and relevance to professional development. Furthermore, it explores barriers hindering the transferability of acquired skills and knowledge to diverse contexts. The findings underscore the enduring emotional resonance of the course experience for alumni, emphasizing feelings over measurable cognitive knowledge retention. While alumni express gratitude for the course, they encounter challenges in articulating its direct contributions to their professional lives, suggesting a gap between experiential learning outcomes and traditional measures of educational and career success.