A little competition never hurt anyone. Years ago, Robert Downey Jr. and Rob Lowe were two teenagers with a rivalry only fit for Hollywood, as the two were unaware they both were destined to be award-winning movie stars. Downey Jr. recently made a guest appearance on The Outsiders star’s “Literally! With Rob Lowe” podcast, where the pair reflected on their experiences as students at the same high school in Santa Monica, Calif., more than four decades ago. “I want to say I was jealous, but that’s not deep enough,” the Iron Man star admitted of his feelings toward Lowe at the time. “I want to sa…