I've only had it happen once or twice, and its been when I've PRed in the 5k and 800m run.
I always get very nervous before my races and feel very timid and not strong throughout a race. When I did get in an aggressive mindset, it made me feel very strong, and possibly what you guys describe "pure hate" as.
But how do I channel this so I can use it when I want to? What gets you guys jacked? I really need to start racing mentally stronger, as my body is there (workouts show it) I just need to run the times now.