Life without a heritage - the intent of the Superboy TV show was to have a fully developed Superboy.

Article by Rennie Cowan

We all know about the #1 rule in the "Smallville" TV Series: no flight, no tights. Quite the contrary to the Superboy TV Series. The intent of the show was to depict a fully-developed Superboy character that mirrored the one seen in the pre-crisis DC line. So by the premiere of the series it was evident that Clark Kent had already discovered most of his powers (if not ALL of them). In fact, he knew he could fly, use heat and x-ray vision, and that bullets could bounce off of him (the bullets bouncing was discovered in the show's tie-in comic book, issue #2). Nevertheless, this didn't eliminate discoveries. Superboy learned that he could be affected by magic, vampirism, alien forces, other super-powered beings and Green Kryptonite (which was introduced in the first season). Red Kryptonite and Bizarro Kryptonite was introduced in the second season.

These random discoveries and phenomenons inspired Superboy to write a journal. In this journal, he would place his thoughts, facts, theories, and many doubts about his powers. However, he was still a fish out of water! He had no inkling of his true heritage--where he was from or why he was here. The rocketship that had sent him to Earth was safely stored in the basement of the Kents' house; the rocketship alone was evidence for the theory that he could have come from another planet. And in issue #1 of 'Superboy: The Comic Book' which told the tale of Superboy's first appearance to the world, Superboy came into contact with an alien life-form that lived inside a meteorite. This alien clued him into the idea that he was in fact an alien.

The waiting was soon over. Well, almost. Only two episodes ever mention Krypton and Kal-El's past, a second season two-part tale titled "Abandon Earth"/"Escape to Earth" (actually, in the episode "Metallo", the planet Krypton and the origin of Kryponite was briefly mentioned as being from a planet Astronomers theorized once existed). In this two-part story, Superboy finally learned about his true heritage, and the aweful fate of Krypton. However, this new-found knowledge turned sour when Superboy found out Jor-El and Lara were really two imposters posing as his parents (Vorok and Mir). They actually ran an unethical cosmic zoo and needed Superboy for their Kryptonian habitat. In the end, Superboy had to make a difficult choice between the knowledge of his true heritage or the life of his college roomate, Andy McCallister. I suppose it's obvious what choice he made. Superboy changed the past in order to salvage the present. Surely, the absence of this heritage brought an element of sympathy to the Superboy character.