Your wave is your own. It rises and falls for no reason you ever need to explain, and your creative depth lives inside it, especially in the low stretches. What you get reliably is a fine-grained read on spirit, yours and other people's. You can feel what mood someone is in, and you can provoke it, tease it, shift it. That is how you find out who belongs in your life. If your provocation only irritates a person, they are not for you. If it opens something in them, they are.
This is Individual circuitry, so what moves through you is mutation, and it spreads by contagion. When you are in the right mood, your passion is infectious and it genuinely changes the people near you.
The rule that makes this liveable is short: if you are not in the mood, do not do it. Do not eat, work, socialise or make love out of obligation. Forcing yourself when the mood is absent produces nothing good and drains what you carry. When you want to be alone, be alone, without apology and without a reason.
The shadow is turning the wave into a weapon or an escape: moodiness that manipulates, making other people responsible for how you feel, or reaching for sex, food or something stronger to outrun the melancholy. You are not a victim of your moods. Let them move, and they will feed you.