Smallville (2001)

S4E19 Blank

A young boy with the ability to erase memories pulls off a heist at the Talon, prompting Clark to pursue him—only for Clark to end up completely forgetting everything. Chloe discovers the situation and steps in to help Clark navigate his powers while ensuring he doesn’t inadvertently expose his true identity. As Clark, Chloe, and Lois work together to locate Kevin, Clark seizes the opportunity of his memory loss to ask Lana out on a date. Meanwhile, Lex seeks to exploit Clark's condition to uncover the mysteries of the caves.