What Ever Happened to SpongeBob?

SpongeBob feels neglected by his friends and decides to leave Bikini Bottom. Along the way, he accidentally bumps his head and loses his memory. SpongeBob wanders away into a new place called New Kelp City and attempts to get a new job, unaware he is becoming a target for a criminal gang known as the Bubble Poppin' Boys, while Patrick, Sandy and a reluctant Squidward try to find him.