That seems to happen to him frequently. Perhaps he doesn’t have the mental acuity for the office.
Trump turns 70 in June, but I think his mental acuity is probably OK.
His knowledgeability, however, is not. He simply does not know enough about the issues of the day. As a result he gets pushed around by interviewers as in this abortion thing. No half-competent pro-life candidate for State Assembly somewhere would have said what Trump said. Similarly back in the debates, Trump answered a question about the Nuclear Triad that revealed, cringingly, that he didn’t have a clue what that was.