After working nine years as a Mathematician, Professor Dr. Lenni Haapasalo has more than thirty-five years of experience as teacher educator. His research interest is to develop elegant practical theories based on radical constructivism, especially concerning links between conceptual and procedural knowledge and taking into account the progressive instrumental genesis. One of his current interests is to develop research-based solutions to solve the deadlock caused by conventional task types when allowing the usage of progressive technology. His dream is to see teacher as a team manager within the “Pit Stop philosophy”. He often refers to his own “Piagetian laboratory”, emphasizing how his theories were reinforced by the experiences among his own children.