Sorry to let you know this but that pounding heart that you feel in your chest when you see that nice buck (never mind big buck...any deer)doesn't go away (at least I hope it won't). This year will be my 35th year hunting and I kind of look forward to that feeling. Just concentrate on your breathing and focus on the job at hand (harvesting the animal). Live for that moment and try to cherish it for there aren't many like it. Know that your practise at the range, all those mags. you've read, all those hunting programs you've watched have come down to that moment. Remember you are the dominate preditor and have confidence in what you are doing. Live it and love it and know you are so fortunate as compared to those that have never had the chance. You are a whitetail hunter. How's that for a pep talk?