I Remember You... Sometimes (S03E23)

Embarrassed when he forgets a client's name, Darrin buys a book to improve his memory. Endora slyly casts a spell on his watch so that when he wears it, Darrin has a perfect memory. Ed Pennybaker, a client, prides himself on his vast knowledge, but Darrin tops him every time. When Darrin takes off his watch, he forgets things, but doesn't get the connection. Samantha invites the Pennybakers and the Tates to dinner. Ed displays his expertise on every subject, but Darrin easily outshines him. Samantha realizes that Darrin may antagonize an important client. She tries to stop him but fails. (iTunes)