At the moment of writing, I am 20 years old software engineer and computer science student. In the last two years, I learned more than during all my conscious living before that. One of the most important things that I realized being a student and software engineer was the importance of a deep understanding of the basic concepts of complex subjects. Especially in those, you spend life doing. Once in university was a course about probability theory. In the process of learning, I left notes and visualizations in the Jupiter notebook. The goal was to build a good understanding of basics while making real word applications modeling. After some time, I realize that my drafts may be better than traditional formal representation, which we usually see in a university. Therefore I moved my notes to the blog.