As a MC fellow I participated in the European Researchers' Night festival which took place in Belgrade, Serbia. It was an exciting experience and a not so trivial task to me to try to explain modern physics, which our technological development in past decades is based on, to a broader audience and especially to the youngest ones. Since I am doing the theory I presented them the very basic principles of quantum mechanics as well as the story about one of the most important effects in condensed matter physics - superconductivity. What is important is that the community showed a big interest and I managed to draw their attention. At the same time I had an opportunity to check my understanding of physics according to the famous Einstein's quote: "If you can't explain it simply, you don't understand it well enough."