My Favorite Martian (1963)

S1E18 Who Am I?

Martin and Tim are heading to meet Professor Eugene Downey, a leading authority on rocket fuel, as Martin hopes the professor can help him return to Mars. However, Martin suddenly gets knocked out by a monkey wrench, resulting in amnesia. He’s unaware of his Martian identity, despite Tim’s attempts to remind him. The only consensus they reach is that Martin needs a doctor. At Dr. Gilbert's office, Martin discovers he can levitate and even vanish, but he dismisses it as magic. Back at home, just as Tim nearly convinces Martin of who he is, another blow to the head from a hammer restores his memory. Unfortunately, they find out that Professor Downey has already left town permanently.