First off, everyone has it but some over come it better then others. You said little info in your post as to when you have it but I will guess it was when you were hunting and the deer was in range.

First thing I do after I settle in a tree, I walk off in my mind my 10, 20, 30, and 40 yrd boundry. Next I think about where the deer will come from and how will I react. I look for the wholes in the woods where I might see them. I also listen the squirrels and birds to adjust my ears to the conditions for the day. This is important because everyday is different. The wind blows different, the ground maybe wetter making the wood quiet or for me the local car traffic is heavier. Bottom line is the woods are new each hunt.

The last thing I do is think about the shot itself. Walk it through your mind. Think about how you will breath as the deer is coming into range. If you been there before, you will swear the deer can here every breath. You know what, you maybe right. Your control of the breathing makes all the difference in the world. I fortunantly hunt where I get to see herds and passing up the small ones while controling my breathing helps a lot. Always think about the shot and how will you handle it.

If it makes any difference, after 20 years I still get excited when I see the deer. If I didn't, I will hang up my bow.