On every animal I've ever killed with a bow, I can not recall ever seeing the arrow hit the animal. I think I'm so focused on aiming and executing the shot that I don't watch the arrow fly. Even though I don't see it hit, I always know if I got a good hit based on the deer's reaction.

I don't think it's necessarily a good thing to watch your arrow fly. It could lead to bad habits and misses. Just my opinion.