Complex sentence: In Jewish mythology, Lailah, the Angel of Conception, lightly taps the infant's upper lip before birth, whereupon the infant forgets the Torah she has taught it.
Split into simpler sentences: In Jewish mythology, Lailah, the Angel of Conception, lightly taps the infant's upper lip before it is born. Once she taps its upper lip, the infant forgets the Torah she has taught it.