Cortisol is super high in the morning, since it's released in order to wake the body up from sleep. Ideally, coffee should be used a few hours after awakening to be better utilized after the cortisol levels have naturally lowered. I think waking up, jacked on cortisol, then drinking a lot of coffee furthers the massive flood of autonomic arousal.
But, we're all different. You have to find what works with your own body.