Clark has fallen pretty hard pretty fast, hasn't he? I foresee problems later with his decision not to reveal that he's an alien, but in his current circumstances, that's a perfectly reasonable decision. I like that he's not just falling for Lois but his attitude about belonging is changing.
And he finally understood something - belonging was not about a planet, but a person.
This line really shows that he's growing. He's gaining a perspective that he didn't have with Lana because she seemed to have emphasized his differences and let him know they were unacceptable, rather than just loving him the way he was. I think Clark's decision to stay must have been influenced by Lois being so readily accepted into the tribe, despite her obvious differences from the rest of their people. He probably figures that if they can accept her as one of them, they will probably accept him as well.
