Dreams involving animals, especially those that appear aggressive, can often symbolize aspects of our subconscious or emotions that we might be grappling with. In your dream, the black horse could represent a powerful force or feeling in your life that feels intimidating or out of control. The setting by the lake in a forest may symbolize a place of reflection and deeper understanding, suggesting that you are in a phase of introspection about your emotions or relationships.

The fact that you were with someone you don’t know in real life might indicate that this situation or feeling is unfamiliar to you, and it could represent an aspect of yourself or a new experience you are encountering. Walking away from the horse could symbolize your desire to distance yourself from these aggressive feelings or situations.

Overall, this dream may be urging you to confront whatever is causing you fear or anxiety rather than avoiding it. Consider what in your waking life feels overwhelming or aggressive, and think about how you might address those feelings or challenges. Embracing them rather than running away may lead to personal growth and a better understanding of yourself.