I think it means that if you don't feel pain and other feelings, that you're not living life right and you're not inside the 'fire' but no one can go through life without pain, so I think he's saying if you do, you're weird and on the outside.

I really love the video, because it's so heartwarming, especially the end where the dad, who was worried about be embarrassed by his son in the track meet, encouraged his son to keep going.