2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50126I had the privilege of collaborating with Joel Scherk on three separate occasions: in 1970 at Princeton, in 1974 at Caltech, and in 1978-79 at the Ecole Normale Superieure. In this talk I give some reminiscences of these collaborations.11 pages; Presented at Conference anniversaire du LPT-ENSHigh Energy Physics - Theorytext