How many seasons you need to catch up on: It's about to start the eighth and final season of the series! [Insert tears of despair here.]Why it's important to start from the beginning: Dexter has had an enormous journey not just as a serial killer, but as a man struggling to find out if he can keep his life together while under the strain of this huge secret. (Hint: The secret is he kills people.) It's definitely worth watching from the start to see his descent and eventual — I hope — redemption.