Joint action and knowledge sharing are fundamental aspects of business model innovation (BMI) for businesses to meet the complex BMI agenda of today; for example, think about 12 independent businesses jointly innovating on the establishment of a new concept of a balanced energy plant project where the businesses have to work in symbioses from the very first moment and further 8 independent business collaborative innovation on the establishment of a new BMI incubator platform. Yet, cognitive science and best practice tools have had little to say on this topic because for many years perception, action, and cognition have been studied without taking their role in social interaction related to BMI seriously. However the establishment of a “room” for social BMI interaction is essential at the very first moment of the meeting between the involved participants – who often are different and unknown to each other. It lays the fundament for knowledge sharing and learning to the BMI project – and the ground for whether the BMI project will succeed and even be implemented. The paper aims to understand the cognitive mechanisms “at the very first moment of the BMI process” supporting participants’ ability and motivation to act together with each other in the BMI projects. The paper address knowledge sharing and learning in high risk and sensitive areas of BMI – where business open their core business, core BM and core competences – and expects trust. The paper provides 2 case studies in 2 different BM projects and BM ecosystems. The research methodology was case research carried out from 2007 to 2015. This paper puts in evidence different understandings related to cognitive mechanisms “at the very first moment of the BMI meeting” between business in BMI projects. The paper seeks to give more understanding of how to support BMI participants’ ability to act together with each other in BMI projects addressing the question How to increase and “speed up” the first moment motivation to achieve knowledge sharing in critical and risky BMI projects? There has not been much research on the cognitive processes and how to establish “room for BMI knowledge sharing” at the very first moment of complex and risky BMI project. This study extends recent stream of BMI research indicating that facilitation and the ability to establish a trusted and secure knowledge and learning sharing BMI platform at the very first moment may be a useful tool for managing BM risk and improving speed in BMI projects. Moving fast along the learning curve in the first moment seems to require some very special arrangement especially when BMI takes place in strategic critical areas. Although initial adoption of early involvement was intended to reduce costs – both in short and long term perspective, results indicated that early involvement serves to reduce perceptions of BMI risk at the businesses involved. The paper illustrates what is at stake and needed for business to exchange knowledge in BMI projects that are complex, are risky and that involves BM´s that are core and strategic to their business.