The internationalisation of higher education through study abroad programmes is a pivotal strategy for cultivating knowledge of the host country and the world. This article explores the long-term impacts of study abroad through the lens of knowledge diplomacy, which emphasises the benefits of understanding the world through transformative international experiences for all involved actors. The article draws upon original data sources on US study abroad experiences in Japan from 1963 to 2012, including a quantitative online survey (n = 259) and 25 qualitative in-depth follow-up interviews. The findings shed light on how participants understand their personal development resulting from their study abroad experience and how their awareness and connectivity become more global, with a lifelong bond to the host country, raised consciousness of the host region and an expanded awareness of the world.