In this article the connection between transfer, interaction and reflective thinking is analyzed, especially within the context of learning mathematics. Attention is paid to the question of how to use or to explore the knowledge that has already been acquired. It may be relevant to make a distinction between the "classical" concept of transfer and the concept in which transfer is viewed as constructive and productive, hence not just applied, but elaborated and explored also. Learning mathematics is considered as a cyclic and continuous process and that means that the knowledge that individual students transfer (use and explore) is a motive to negotiate with each other about the merits of the diverse procedures and approaches that the participants were opting for. This dialogue provides an interesting base for critical reflection on the thinking trajectory, approach and insights that each individual student originally preferred and elaborated. Dialogue converts into reflection and therefore reflection is viewed as internalized dialogue. And reflection leads to transfer on a higher level and so on: learning mathematics is a cyclic and continuous process.