Three-Act Plot Analysis
We learn everything about the Aziz and Sinai families so that we're ready when Saleem is born. One day while sneaking around, he discovers that he has telepathy, but it's the knock on the head that introduces him to the Midnight's Children that is the game changer. Everything is different now.
Saleem creates The Midnight's Children Club, and for the first time all of these X-Men-esque children get to talk to each other. That all falls apart when Saleem finds out that he and Shiva (his archrival) were switched at birth. So now he has no friends. Then the first Indo Pakistani war comes and kills his whole family. Now he has no family. Oh, and he lost his memory. It couldn't get much worse, could it?
Gradually, Saleem gets his memory back. He has a kid, which signals the end of his importance, and his future ends when The Widow removes his testicles. He dies on his 31st birthday right after getting married to Padma.