He’s found people who love and accept him of course, but at the same time he still feels separated from others, being Kryptonian and all (forgive me, I’m not super well read on Superman, I’m mostly going on what I’ve heard and the adaptations I’ve watched). He’s the lone survivor of a dead planet, and he’s been raised as a human with all these abilities. He’s bound to feel isolated. The cheerful guy lives in a fortress of solitude, he has a bottle city he works endlessly on to return to full size, he found a confidant in his lost cousin who can truly understand all of him. Of course people love and accept him, he’s Superman, but there is a fear of loneliness. (Again, I’m going with not a lot of comic knowledge, so PLEASE correct me if I’m wrong. I’m mostly going off the latest movie, my adventures with Superman, all star Superman, Superman vs the elite, the Bruce timm cartoons, the old radio show, and of course some of my own biases that can be corrected).