Tom H,
Your mention of fear/pressure when playing on great courses one may only play once or a handful of times really struck a chord with me. If a clerical error resulted in a member of Augusta National inviting me over for a single round, I'd feel a lot of pressure knowing I'd never have another chance at it. I might not really care if I screwed up on comparatively mundane holes like the 1st, but I'd hate to dump in the water on 12, hook it into the woods on 13 or 15, chunk it into the front bunker on 18, etc. If I played Cypress I'd feel like you on the 16th, but know I had to go for the green no matter the weather or how I was playing, because it might be my one and only shot.
However, on courses I know I'll return to (or at least be able to) my feelings are different. On my second time to TOC last year, I played a shot nearly everyone would advise against, and hit a 7 iron from the wispy rough on the left, right over the Road Bunker trying to hold the green. Why in the world would I do that? Well, the first time I played I was so wound up on that hole worrying about the places everyone says you shouldn't go, the road and the Road Bunker, that I duck hooked it 30 yards left of the green into some deep rough, and doubled it. I had decided this time to not worry about it. After all, I figure I'll play that hole at least a few more times in my life, eventually I'm going to put it on the road or in that bunker. So what, I'd hate to play it a dozen times and have never faced a shot from the Road Bunker or off the road. I took care of playing off the road last time (it is not easy to hold that green :-)) and got my par. So maybe next time I'll put it in the bunker and see if I can get up and down from there. That actually makes a better story than if I say I played it safe out to the right and chipped it up and down, or even that I held the green and two putted for the par.
The other time I really felt pressure that trip was the 16th at Carnoustie. First time I was there, I aced it in a 25 mph crosswind, and it was my first ace. I'd just had my second ace a few weeks before my trip, so I kinda figured I'd used up my quota for awhile, so my main goal was to attempt to keep my lifetime average on the hole below par. It was raining (heavily at times) that day, and I used a 4 iron same as I did for the ace. I don't know how I hit it square and straight with as tight as I felt, but I hit it right at the flag. For a moment I thought I might do it again, until it landed just short of the green and stayed there. I knew I needed another club due to the fact I'd see no roll, but I couldn't bring myself to not hit the same club as before due to some sort of inner superstition. Damned if I didn't make a pretty long putt from off the green for a 2, though! Lifetime average on #16 Carnoustie: 1.5. Beat that, Tiger! More importantly, I finished par, bogey to end even for 16-18. Last time I'd gone par-par to finish -2, and my caddie told me he'd been carrying for 40 years and never seen anyone finish the final three at -2, and that's still my lifetime total there too. I know I'll feel even MORE pressure next time I'm on 16 tee, as well as 17 & 18, to keep these records intact. I know they don't mean anything at all in the big scheme of things, especially I failed to break 80 either time. But while I know there's no way I'll ever put together 18 holes there that compete with a pro (unless you count the last couple guys on opening day of the Open) at least when I watch the pros and see no one touch my average on 16 or totals on 16-18, I can feel that at least on one or two occasions, for a couple holes, I can take 'em all on :-)