I can feel a big difference when I correct myself. When I get really tired, I'm usually way up on my toes and it actually relieves my legs a little when I notice and make the change.

indigoiis- I also talk to myself when I ride. Sometimes it's mantras to remind myself of technique, other times I curse the stupid hill for being so long, steep, etc. Sometimes, I just make up stupid songs to try to distract myself from how hard I'm working. I've been caught by people passing me a couple of times. Talk about embarassing!!