The man from Inverness has won a World Golf Championship event and plays with household names on the PGA Tour every week but said that none of that had prepared him for such an experience at his home major.
Knox said: “I felt good out there but my swing was just like I had too much tension.
The Scot carded a two-over par 73 to finish the day seven shots behind first-round leader Kevin Kisner.
Kisner, the runner up when Knox won that WGC-HSBC Champions event in Shanghai in 2015, made the most of the calmer morning conditions on the Angus coast.
Knox added: “I knew it was going to be an uncomfortable round for me.
“I was never going to feel like I was out playing with my buddies, just freewheeling it, and that’s understandable. Major championship, The Open in Scotland, playing with your hero, you’re never going to feel like you’re just winging it.
“He [Woods] is a person I’ve seen on the range in the past, but he’s almost like a mythical figure.”
Former World No 1 Woods was playing in his first Open since 2015 and huge galleries followed him as he set out on his quest for a 15th major title.
But there was plenty of vocal support for Knox, who said he eventually settled into the round and enjoyed the backing and the chance to chat to Woods and study the way he plotted his way around the demanding Carnoustie links,
“Obviously, I’ve won three times. I’ve played in front of loads of people for the last eight years. But I think it’s a little different knowing who you’re playing with. I think he’s the best golfer of all time. He’s definitely the person I looked up to. So getting to play with him is pretty unique.”
Woods finished his round level par 71 but, on a day when few of the big names able to rise to the challenge set by the sun-baked links, he believes he can still apply pressure to the men currently setting the pace.
He will be aiming to peg back past Open champions Rory McIlroy and Zach Johnson, who are both on two-under, alongside 2016 Masters winner Danny Willett, Jon Rahm and last year’s USPGA winner Justin Thomas.
Woods said: “I played better than the score indicates because I had two eight irons into both par-5s today, and I end up with par on both of those.
“If I just clean up those two holes and play them the way I’m supposed to play them, I think I’d probably have the best round in the afternoon.”
Defending champion Jordan Spieth finished on one-over 72, six shots off the lead.
He was three under par after 14 holes before running up a double bogey on the 15th, dropping another shot on the 16th and scrambling for a bogey on the 18th after driving into the Barry Burn.