Why people are drawn to teaching has been a focal research area. However, previous studies seem to centre on the traditional conceptualisations of intrinsic, altruistic, and extrinsic motivations as well as some other similar categorisations. This study attempts to discuss the issue from a different conceptual stance, proposing a distinction between the "triggers" and the "drivers". The influences on the motivation for joining teaching were explored through in-depth interviews with 26 student teachers. Results show that student teachers' motivations for joining teaching in Singapore may differ in important ways from that of their counterparts in other places. More importantly, the results highlighted differences between "triggers" and "drivers" as well as the inter-relatedness between them. Some practical implications are drawn for teacher education both within Singapore and internationally.