I've got no business trying to add my thoughts to this thread, having never driven a stock car in competition, but here I go anyhow....
This thread (which I find very interesting) reminds me of how I use to tell my dad and George Curtis (guy we sat with up in turn 1 at Flemington when I was around 13 or so...) that if I ever had a stock car, it would be a crappy primer color and would have the numbers painted like some kid found a paint can and a brush... I wanted to set low expectations for the first time out, with the hopes of over achieving! Figured if I had some beautifully painted car, professionally lettered, that folks would expect me to win right out of the gate... and anything less than a win would have been disappointing... Also figured if I did win, if the car looked that good, everyone would say, "Of course he won... Look at how nice that car is.... Anyone could win in that thing!"
The other thought that this thread brought up, is something I hadn't thought about in quite a few years, and that was my attempt at racing 250 Amateur Motorcross back in 78 & 79. I would have my dad drop me and my bike off at the front gate at Englishtown, with my riding gear and essentials in a milk crate bungie corded to the seat. I would push my bike over to the ticket window... pay admission... sign in as a rider/class, and then would push the bike over to a friend who I worked with at East Coast Kawasaki who had his truck/tent/tools. I didn't want the pressure of friends and family being there. Told family, and my girlfriend at the time that I didn't want them there... Had a predetermined time for my dad to come pick me up.
Talk about getting nervous... I'd roll up to the starting gate and pick a slot... and then I'd sit there watching the moto that was going on at the time, waiting for it to end before they dropped the gate on my moto. I watched them out there thinking, those SOB's are freakin' nuts.... Holy crap... I'm next... Then I'd get that weird feeling of, "am I really here... Is this really about to happen...." and then I'd "over" notice my breathing in the helmet... whether my helmet was snugged up... was I in 1st gear.... Then once the gate dropped, none of that mattered.
I wasn't very good, but I can agree that once the green was out (or in my case, once the gate dropped), I didn't have time to be nervous, or 2nd guess anything... It was just a matter of trying to pass the guy in front of my... and how many more laps are there because my arms were about to fall off!