Giantfan
You are very wrong in thinking that you can't know the course conditions by playing it a number of times. While it is true that the wind is random, playing it a few dozen times gives you a feel of pretty much all the wind directions and how the effect your ball.
The real key though is putting. That doesn't change from game to game. If you know the greens and where the breaks are you are able to putt better and also know where to hit the ball for the easy putts. Play Congressional a few times, there are at least four holes that have backstops that return the ball almost to the hole, it's a matter of knowing where to land the ball on the green and if you do so you end up with a putt from a few feet.
I'm not in the class of the players you are talking about, but I have played with many of them and witnessed great scores from them and usually it is because of their putting. I struggle to make 8 to 10 foot putts while their routinely knock in 20 footers.
I qualified for the US Open for the past few years and I have a 58 posted for the British Open this year, I qualified for it last year as well. I play a lot and while I don['t chart the greens as thoroughly as many, I do try to remember the subtle breaks and ridges that are important to play away from or at.
If you want to be a good player you have to do all these things and you have to have the best clubs and balls available. If you are here to have fun, nothing more is required than what WGT has given to you.