It may not be totally apparent but you cannot really apply strategy until you learn to manage your emotions. Anger, anxiety cannot be succesfully managed by white knuckling or force of will. And patience cannot be sustained without understanding. Think of it. There are enough examples around. The underlying issues are imagined fears which is protected by the ego. The intense pressure from tournament chess quickly reveals our flaws.
And this too has a systemic effect. If this is not true, then why havent we got a plan yet for our chess development?