I grew up among the teachers. Therefore, I am happy to be given the opportunity to speak in front of students of the faculty of education, at Universitas Mulawarwan (UNMUL), Samarinda. A day before, in Balikpapan, I was also given the opportunity to be a keynote speaker at the Conference organized by Faculty of Mathematics and Natural Sciences of UNMUL. Prof. Brenny van Groesen from Twente University, the Netherlands was also present as a keynote speaker. Alhamdullilah, meeting with friends in Balikpapan and Samarinda can open opportunities for collaboration and cooperation with UTM.