Medicine in the 20th century "tamed" most of the incurable infectious diseases of the past. For some, it offered complete healing, while for others, it provided management and symptom relief. However, the recent COVID-19 pandemic reminded us that our everyday life can be dramatically disrupted by new and unknown infectious diseases. Thus, we were reminded of how a virus can push healthcare systems to the brink of collapse and force us to take protective measures. I use the word "reminded" because humans, like other forms of life on our planet, have encountered and been infected by unknown viruses for millions of years.

In the book you are holding in your hands, I attempt to provide a broader perspective through my own prism on these peculiar "exotic" parasites and their significance in shaping human existence and life as we know it on this planet. Amid historical epidemics and scientific-philosophical questions about the essence of life, I strive to introduce the not unjustly misunderstood entities of viruses. It is worth learning about them because through them, we will be able to see reflections of our own journey and existence.