Rolf Widere (1902-1996) was an extraordinary scientist and inventor. Whilst still a student of engineering he put forward the principles for a "betatron accelerator" and successfully operated the first "linear accelerator" (linac). In 1943 he patented the principle of "colliding storage rings" and in 1945 he submitted a patent which included a complete theory of the "synchrotron." After the War he began to build betatrons for technical and medical applications at BBC in Swizerland where he developed an interesting "two components theory" on the effects of radiation on living cells. For 20 years he taught accelerator physics at the ETH Zurich. He was the subject of occasional reproaches for having worked for the German Luftwaffe during the War, when he built a betatron in Hamburg. This autobiography includes his reasons, and his statements should provide valuable historic insights.