The 100th anniversary of Bruno Touschek’s birth also marks 60 years since the first beams of electrons and positrons circulated in AdA, the first ever matter-antimatter collider, built in Frascati National Laboratories following Touschek’s visionary proposal of February 1960. Touschek’s path to such idea is briefly outlined, beginning with his early years as a student—first in Vienna and later in Germany—through his first experiences with Rolf Widerøe’s betatron and the electron synchrotron accelerator in Glasgow after the war, along with his relationships with the fathers of modern physics in Europe, to his arrival in Italy, where crucial reflections during the 1950s led him to the profound belief that matter-antimatter annihilations should become a primary goal for future physics. Based on these premises, Touschek and his collaborators dared to take on the challenge of realizing what at the time seemed an “unthinkable idea”: keep beams of electrons and positron circulating for hours in the vacuum chamber of a storage ring and making them collide.