Few heroes in the DC Universe look up to Superman as much as Nightwing does. An event from Dick Grayson's days as Robin sheds a light on how his lifetime appreciation for the Man of Steel got its start.
As one of the most beloved heroes around, Superman has a number of fans all across the universe. But it isn't just the people Clark Kent saves on a daily basis who look up to the hero as others in the hero community even look up to Superman. His relentless determination, earnest attitude, and can-do spirit serve as a source of inspiration to younger generations of heroes. But, no hero looks up to Clark more than Dick, who's been a huge fan of Superman since he was Robin. His hero worship can even be seen in the identity he took on after leaving his position as the Boy Wonder, with Superman giving Nightwing his hero name.
Fans curious as to how Nightwing became such a huge fan of Superman need only look at a short story presented in Superman #700. The story "Geometry" by Dan Jurgens and Norm Rapmund takes place early in Dick's career as Robin, where Batman is shown to not trust Dick to fight crime independently yet. But once Grayson discovers a gang of smugglers in Gotham's harbor, he sneaks out in the middle of the night to try and take them down on his own. The young hero gets in over his head and is nearly killed until Superman arrives to save Robin and stop the smugglers. Clark gives Dick a lift back to Wayne Manor and helps him sneak back in just as Bruce arrives back from a charity function. Superman even provides Robin with an alibi by doing his geometry homework in an instant.
With Batman being the World's Greatest Detective, he easily deduces the events that actually transpired, but he lets it slide knowing Robin was in good hands. Still, the team-up between the Man of Steel and the Boy Wonder serves as a good origin for Nightwing and Superman's relationship. Not just because Superman bailed him out of a serious jam, but because the hero showed Robin that there was another path of heroism that wasn't as strict as Batman's.
Though Bruce helped Dick after the most tragic moment in his life, the two wound up coming into conflict more often than not. Batman hadn't had a partner before nor had he ever raised a child, so Dick was kept on an extremely short leash. But Dick is a free spirit and wasn't thriving under the more rigid structure demanded by Batman. So, Robin's unlikely mission with Superman showed him that not all heroes were as uptight as Batman and that they could even bend the rules. For Dick, Clark was basically a "cool uncle" type to Bruce's "strict parent" and that's the sort of thing that can leave a lasting impact. Superman helping Dick out a serious jam is a great way of justifying Nightwing's justifying idolization.