It's not from Superman. It predates the Stussy logo. Why did schoolchildren around the globe get infatuated with this stylized S? Vice takes a (kinda shallow) dive into the provenance of the stylized S.
Two sets of three vertical lines, connected with points at the top and lines in the center. Variants involve how the ends of the S are stylized (pointy vs. blunt).
I can personally attest to at least 1978, when we would pass notes in middle school with the S forming a little signature that said "Sorry So Sloppy," usually below a demand to list the recipient's best friends in order ("#1. YOU!!!"). I may try to find some old notes with it (yes, I still have notes from middle school). Please note this was distinct from the S in the KISS logo, which was carved and scrawled with impunity onto surfaces around school.
Let's get to the bottom of this! Comments welcome.