Your account of when you get ready to ride and your increased heart rate is very interesting. It reminds me of a story Anthony Robbins told about a famous singer client of his. As I recall, he said she was having anxiety about performing and it was getting to the point where she couldn't perform any more. He asked her to describe what happens when shes about to perform. She said she starts feeling nervous, then her heart starts beating faster, then she starts sweating, then she starts shaking and now can't perform. Anthony Robbins goes on to say that he was on a plane with Bruce Springsteen. And they got to talking and he asked Bruce Springsteen what it feels like when he's about to perform. He said he starts feeling anxious, then his heart starts beating faster, then he sweats, then he starts shaking and he can't wait to get on stage.
I can't remember what the Anthony Robbins point was about but maybe Perspective. Maybe C-Cat is just excited about riding and no PSTD at all.
Like C-Cat I too get a little stressed about riding (due to traffic), til I'm 4 miles out then it's Awesome.