1. Kaldur was the first person Conner ever touched, so it was apt that he would be the last too.
2. Kaldur's pretty sure that he can't survive having his heart broken twice, so he carefully avoids noticing how happy Superboy is with Miss Martian.
3. Superboy knows, abstractly, how to swim, from his CADMUS lessons, but he always avoids the water because he knows that he could never be as graceful as Kaldur in his element.
4. Kaldur is unsure why Conner comes to him for help with human culture - sure, he's been here for longer than the clone or M'gann, and he can understand being wary of Robin and Wally's advice, but that still leaves Artemis - but he remembers the loneliness of a new world and knows that it must be so much worse for Superboy because he at least had Tula and Garth and he answers the questions without complaint.
5. Kaldur should be the one he's the least gentle with - after all he can sustain much harder hits than anyone of the others - so Kaldur's confused when Black Canary yells at Superboy for holding back too much during their spar.
6. If this were a fairytale they would have ridden off into the sunset planning the marriage, but this isn't a fairytale, so instead, the two of them are sitting in painfully awkward silence at the cave, waiting for the rest of the team to show up.
7. The first time either of them say 'I love you' they're in the infirmary and Conner is unconscious after his first exposure to kryptonite.
8. Orrin isn't sure what to think when the clone (what was his name again? Caleb? Coffler?) comes to him, carefully holding half a dozen seashell's (from Kaldur, he says, and why would he lie?) and asking what they mean (courtship, admiration, friendship, attraction, hope, love?).
9. In the end, it isn't Batman, or Wonder Woman, or Robin, or Black Canary (although certainly not for lack of trying) that convinces Superman to train Superboy (not for lack of trying) but the sight of him gently kissing his team leader.
10. For as long as he can remember (for as long as he has existed) Superboy has been characterised by his rage, and it's something he holds to desperately, for lack of any other grounding, even as Kaldur destroys it almost inadvertently, with calm, soothing words.