The metaphor of the leaking pipeline is sometimes used to suggest that some students are lost for STEM as they advance through the educational system. This paper follows a cohort of upper-secondary school students with an interest in STEM from 18 months before their completion of upper-secondary until three years after their completion. Adopting a mixed-methods design, it follows the students' reflections and interests concerning their choice of higher education programme within and/or outside STEM. Only 22% of the students expressed the same interest during the whole period, and 56% changed between different groups of studies, e.g. between STEM and HEALTH. The students' trajectories showed that the leaking-pipeline metaphor is misleading because it suggests a linear and one-way movement, while there were students moving in as well as out of STEM trajectories. The students' reflections showed identity issues at the level of ego identity, the personal identity and the social identity (Coté and Levine). Particular incidents in the students' lives and in the outreach programme they were involved in sparked interests and reflections. These incidents should be considered as elements in a continuous reflection concerning who they are and where they would like to go rather than as "critical moments."