When race day arrives, it is what it is. You can't worry about what you did or didn't do. One should have a good idea what they can achieve
and then go do it. I don't try and set the table early. This is important. For a five mile race I really don't worry if I'm 10 seconds off or so either way.
The big thing is finding the rhythm you need to power through the middle stages. Then you set the table. Just before 4 miles you have to know your going to be gassed. You have to find someone, or a group and hang on. The mind set is everyone is hurting so you have to determine how much hurt you can handle. If I understand one thing it is I'm going to make a move. Succeed or fail you have to gauge your Kentucky windage and air it out for the tape.
Seldom do I feel dissappointed if I did my best with what I have and laid it on the line. If I want to do better, obviously I would need to alter my training.