You'll find a lot of runners who'll often say that some of their best runs are when they can't be bothered and force themselves to go out, and feel they're running really slow and then look at their watch and realise they're hitting personal records, then other times they can be feeling great, running at what feels like a fast tempo pace, then look and realise it's slower than their easy slow pace.
I think that for those of us that don't live and breathe running it can be hard to get a real feel for these things. Obviously if it's your life and you have your diet/training absolutely nailed on it's probably a bit more consistant.
With the hunger thing it's a tricky one to advise, i'm not sure whether it's best to give in to that and eat, or whether if you force yourself to ignore it then your body will just get used to it. I'm gonna tab
@Somnambulist in here, i know he doesn't usually appear but he always seems very knowledgable on nutrition so might have some good insight.