"Cuando miras al lado oscuro, cuidadoso debes ser. Pues el lado oscuro mira de vuelta."

Simplified Meaning:

Thinking about negative or harmful things too much can be dangerous because they can start to influence you. Picture yourself standing in front of a dark, mysterious forest. If you stare into the darkness for too long, you might start to feel drawn into it, or it might begin to feel like the darkness is somehow noticing you too. This idea can be applied to our thoughts and actions; if you spend a lot of time focusing on bad thoughts or temptations, they might start to affect your behavior. For example, if you always think about anger or revenge, you might become more negative and act in ways that hurt others. It's important to stay aware of where your attention goes and make sure you're not letting harmful thoughts take over. Instead, try to focus on positive and healthy things that help you grow and stay happy.