Former President Trump at rally.Scott Olson/Getty ImagesDonald Trump mistakenly called Elon Musk by the wrong name at a rally on Saturday.The former president referred to the SpaceX CEO as "Leon" during a speech in Wisconsin.It comes after Trump's former biographer said he was "hyper-aware" people were picking up on his apparent mental lapses.Former president Donald Trump mistakenly called Elon Musk by the wrong name at a rally in Wisconsin on Saturday.The former president referred to Musk as "Leon" while praising the SpaceX CEO over his plan to bring two stranded astronauts back from the International Space Station."Boeing had a little hard time, so they are going to save — Leon's going to send up a rocket," Trump said.