Tom,
I feel lucky to have played about 70 of the top 100 in the US once, much less multiple times, so having the opportunity to change my mind is rare. I suspect thats the case for most, as perhaps 0.0001% of golfers are so well traveled.
I have had a change of mind on the few occaisions. I think there can be several external reasons, including course exposure (Pinehurst after hosting a few opens) or personal memories (career best as mentioned, or playing a great course with you son, dad, whatever for the first time)
But, for the 1500 devotees of this site, or any golf architect who continues to study the craft, I think it can change as we get personal exposure to more courses, and as our gca knowledge increases and/or goes through phases of likes and dislikes.
For me, Pinehurst No.2 went from okay in the 70's to great by the 90's. They did restore some of the wire grass, but I also think I knew more about architecture, Ross, etc. through books and study.
Recently, I played Hazeltine and Peachtree again. I had recalled Peachtree as a mundane course, but last spring I liked it more. I began noticing that RTJ had some great internal green contours, scale, and some neat stuff around the greens I had never given him credit for. (I knew he had large rolling greens, but I was studying exactly how he did it in more detail this time)
On the flip side, I loved the non traditional Pete Dye (vs. "standard" RTJ) look back in the 70's. Now, having seen it more, I liked Long Cove and Harbor Town less on second plays - HT made LC look sadly overshaped, and I liked the HT gimmicks like U shaped greens less this time (and I am not against gimmicks, but is HT 9 as good as CD7?).
While I really don't keep a rank list in my head, if I did, Peachtree might have vaulted 100 spots, LC went down maybe 50 and HT about 25. Hazeltine stayed off my top 100, but I did come away with a new appreciation for RTJ and the course.
I actually think your opinions in a revised "Confidential Guide at 55 rather than 25" might be quite different if you made the same tour, with many courses changing up or down a few notches on the Doak scale. While your self exposure to much of the world's best set your philosophy strongly, its hard to believe that your opinions haven't changed as you have seen and created more. I think it should have changed, or you are in peril of going stale as a designer!
I sense from your posts that your philosophy is constantly being tweaked, although I might be reading between the lines a bit on things like backing off "tough golf" a bit (how natural is that when getting older?)
Doesn't life experience change relative opinions for all of us?