"Mantén tus planes tan oscuros como la noche, y cuando te muevas, cae como un rayo."

Simplified Meaning:

When you are working on something important, it's often best to keep your ideas and preparations private, just like you can't see anything in the dark of night. By not sharing too much, you avoid unnecessary interference or opposition. Then, when you are ready to act, do so boldly and quickly, surprising everyone, like a loud and sudden thunderbolt in a storm. Imagine you're working on a new invention. If you tell everyone about your plans too soon, someone might try to steal your idea or discourage you. But if you keep your project to yourself until it's ready, and then launch it suddenly, you'll catch everyone's attention and possibly gain a big advantage. This approach helps in everyday tasks too; for instance, if you're planning a surprise for a friend, keeping it secret ensures the surprise really has an impact when you finally reveal it. This quote teaches us the value of being strategic and unpredictable in our actions to achieve success.