Readers of this volume are invited on a journey through a logician's life, as witnessed by his colleagues and friends. They will have the opportunity to immerse themselves in the regions of set theory, arithmetic, data analysis, algebra, fuzzy logic and other topics that Petr Hajek has shared with the contributors. Each of the contributions is unique in its approach as well as its personal envoi, helping to create a full-blooded, vivid and genuine picture of the man who has been so emphatically influential to so many of us. Mature and fresh ideas blend in the texts which will, hopefully, make an interesting and enjoyable reading for Petr Hajek as well as for any keen logician.