It's a bonus if shows like The A-Team explain their setup with a handy voice-over in the opening credits. Arguably, this is the reason why network television has historically favored episodic storytelling over more serialized ones the idea is that the episodes can be shown out of order and that viewers can just watch episodes at random with no need for context outside of the forty-five minute block. With weekly television, there is a tendency to underestimate the audience. Because remembering what happens over the course of a whole thirty minutes or, god forbid, an hour, is too difficult for your general media consumer, there is a handy little device called a Flashback that can be used to rewind, oh, five minutes or so to say, 'Hey! This just happened, moron!' It may also come from an ancient survey that stated that Americans change the channel 20 times every minute on average.
Sort of like how executives think Viewers Are Morons, they also think you have the memory of a goldfish, which, according to an incorrect urban legend, lasts about three seconds.
