You can just see it in his eyes. It's a combination of fear, disbelief in what he's seeing, discomfort and general awesomeness blended together. It's like he's saying, "Holy crap what did I just get myself into oh my god this is fantastic wait how long can I last before I pass out."
Photographer Blair Bunting was able to take a joy ride with the Thunderbirds and it looks like it was so much fun. Like an unreal amount of fun. Bunting told us what it was like to experience a force of 9G:
Now let me try my best to explain what 9 G's feels like… Firstly, in no way is it comfortable, not even close. I began to feel my face melting away as the skin in my cheeks pulled down to my mouth. The color from my vision was the next thing to fade away, first the reds, then the greens. Squeezing like hell, I did everything I could to get air into my lungs as the G-suit wrenched it out. With all the colour of a 1950s television set, the next thing I noticed was that waves were starting to develop in my vision and a vignette appeared.
All the while I am listening to the pilot's breathing and trying my hardest to match it. At any point I could relax and immediately be unconscious, only to wake up and wonder where I am, but I had trained too hard to let this happen. Then, just as G's set had set in, they began to leave and normalcy appeared. However, if I were to relax at that point, the blood would leave my brain to fast and knock me out as well, so I continually squeeze as the G's lift and my body slowly returns to what sanity it had left.
I'm going to say it was worth it for the ride of a lifetime. Read more about his trip here.