When Christopher Reeve discovered the art of acting he was sufering a bad moment, and I think this help Chris to fogot about this problem. He took part in a lot of films and series, but the best were "Smallville" and "Supreman". In this ones, he acted like a hero.
After Christopher had his horrible accident, become paralytic and the "Paralysis Fundation" appeared, Chris become a real hero and this time it wasn't fiction. For me, Chris become a hero for lots of razosn but the one that impress me a lot, apart of his surviaval is that he helped and enjoyed lots of people that were in his same situation, from his wheelchair.
From my point of view the song "It's not easy" represents Chistopher's life after his accident. I think the song try to said to us that Superman could fly and that he was very strength, but also heroes as the great Superman could fell down and when that happened they have to stand up again and go on.