I actually started reading some of the well-known books first...
And realized I had played junior interclubs at Salem CC, Myopia, and Essex CC...all great and unique places.
Coming from the same background as Brad, our home club's Junior Inter-Club matches at Salem CC, Myopia HC, Essex CC, Kernwood CC, Ipswitch CC, Turner Hill, Georgetown Club... specifically the first three for obvious reasons.
Beyond that... I'd have to say the first "big" tour-style course I played would be Kapalua Plantation... some architecture worthwhile there, especially with the greens.
Then went to Ireland... Ballybunion and Carne specifically being big influences, then this past summer, Portmarnock, County Down and Portrush far and away advanced my Architectural knowledge.
I think the difference between me and Brad was that I always recognized GCA in these old-style courses, I just never got so much into it as him until recently. I am just now starting to read the same books he was reading then.