So I happen to have a sixth-grader, and we discussed this on the ride to school today.
I stated my opinion that it was fine for us to talk about colleges if she liked, but it was really too early to decide anything. She responded, wait, she did have a favorite college! I asked which, and she ultimately needed me to remind her what was the college she liked for architecture (USC, by the way–I think she also forgot she had wanted a college in California).
That seems about right to me. Again, not a problem that she is thinking about architecture or California or whatever. But not obsessively, and indeed not enough to actually really remember once much time passes.
And in fact if 5 years from now she is still interested in exploring good colleges for architecture in California, USC will still be waiting.