Answering this can be very humbling for some. I have missed a few. I would rather miss than wound. I have done both. In fact about 4 years ago I shot 4 deer that I could not find. That was very discouraging and I had a hard time accepting it. I stopped hunting and worked on my shooting until I felt confident to go back to the woods. Since then I have put heart shots on every deer except one.
What had me so worked up was at the time, I had total confidence in my hunting set up, stand placement, shot selection, ect. But when I released the arrow it was not going where I was looking.