I've always been fascinated by the energy and momentum leading up to the premiere in opera performances. There are some singers with whom I have worked, who seem like they are absolutely dreadful at the first musical rehearsal, prompting the question (inside my head) of how on earth this person is working. However, by the premiere, they pull out a fabulous performance and blow everybody away. (Not everyone of course - some people just always suck). I am one of those people that basically gives 110% from the first day of rehearsal, and I find that it sometimes this backfires, in that I have lost my momentum and concentration by the premiere, and the performance was better at one of the dress rehearsals or something.
With Antigone, we had a rather odd schedule, because our conductor had to go away for a bit to conduct elsewhere, so we had a pre dress rehearsal, then 4 days off, then a dress rehearsal, then 2 days off, then the premiere. And for whatever reason, this schedule seemed to do wonderful things for everyone, because the premiere went extremely well. Everyone sang wonderfully, and had a huge amount of concentration and the premiere was actually better than the dress rehearsal - the best performance we'd had so far. I saw Rene Jacobs at the intermission and he said "it's going so well, it scares me a little!" but the second half continued in this way, and in the end, it could really only be considered a success.
For me, personally, I was glad that I was able to pull out my best performance for the actual performance, because this is not always the case for me. I have weird issues with momentum and probably need to be better about not giving too much in the dress rehearsal even though there is almost always a full audience. It's about the singer learning to trust herself, knowing that she can pull out all the stops in the performance without having to demonstrate that beforehand.
Thank you for all your comments about my cold - other than a few sniffles and some dry mouth, it had pretty much vanished by the premiere, and having sung the dress rehearsal sick probably added to my ability to have good momentum to do better in the premiere. 2 down, three to go, and then home at long last.