The Save: ...because, of course, his real name is Manoj Nelliyattu Shyamalan. The "Night" was an affection from student days.
It's served him well, with its connotations of dread merging seamlessly with the subject matter of The Sixth Sense. Now, however, it's possible that he could get people to take him a lot more serious by going back to his birth name.
Callow Larry Fisburne gained newfound maturity as Laurence Fisburne. Movie star Dwayne Johnson got parts that moonlighting wrestler The Rock could only dream of. Prince only really became popular after becoming Symbol...well, maybe not that one, but you get the point.
Potential Twist: Chinese whispers result in Hollywood signwriters mistakenly thinking Shyamalan has chosen a symbol for his name. Henceforth, he is known as ~