Video link: http://espn.go.com/video/clip?id=8450488
additional notes: Edit
We talked about that he's a prideful man, but actually he has come around and admit & repent his selfishness. He sees being able to take care of his daughter as a privilege. He described the letter he was writing as a way to repent and he did not want to hide this dirty secret (how he wanted to abort Parsley and his grieve) from her. He also said that before he was worried that people would think that his daughter's disability reflects him. Now, he see his daughter as a mirror i.e., he sees the imperfection and selfishness in himself.
I liked the story a lot. We all have things we are prideful of and dirty/negative thoughts that we try to hide from others and even ourselves. I admire his courage to admit his own problems and turn around to fully love and embrace his daughter that he once seen as an imperfection in his life. The video motivates me to examine my own value and inspires me to love others selflessly. People may have a different take on this video, but I think the selfless love is one of the key points in this video.
Just to clarify, they did not run 321 miles in one day... They ran many marathons together, and altogether it added up to 321 miles.
For the last marathon, I think there are two reasons from the video. First, there is a symbolic meaning of reaching 321 miles together since down syndrome is caused by a 3rd (extra) copy of chromosome 21. They have reached this symbolic number. The second reason, which I think is the main reason, is that Heath used to think that he has to take care of Parsley for the rest of his life. They formed a team and ran together so Heath can push her (signifying giving her support, physically and mentally). However, in the process, he realized that he may not get to take care of Parsley for the rest of his life. She's growing up, and one day she will not need him (as much?). I think by stopping pushing her in the race, he is recognizing her development and the fact that her needs are changing. She may not need the same type of support anymore. I am not sure if I have expressed it clearly, but it's a very subtle change of perspective. I think the reason he's stopping pushing her in the race is more on the symbolic meaning of this action rather than the physical labour.