ENERGY AND EMOTIONS
That doesn't mean if you're sad and hurting because someone died, you need to shift your "energy" to try and make yourself happy, because that will not work. In such an instance, I would try to recall a "thought" of that person that makes you smile or laugh. This will help you to recall more pleasant memories (thoughts), causing a domino effect of "positive energy," which will gently change your "emotional" status at a pace that's right for you. Where a shift would work immediately is if someone really ticked you off about something minor, and you let your "emotions" spiral out of control. This would be a good time to take a breath and guide your thoughts to something upbeat and positive.