Dreams featuring people from your past can often evoke strong emotions and memories. Seeing a girl you haven't interacted with in 13 years, especially with a friendly smile, may suggest a longing for connection or unresolved feelings from that time in your life.

Her presence in your dream might symbolize nostalgia or a desire to revisit a part of your past that brought you joy. The friendly smile can indicate positive feelings associated with that memory, suggesting that you might be seeking warmth and companionship in your current life.

Consider reflecting on what this person and that time period represent for you. Are there aspects of your past that you miss or wish to reconnect with? Alternatively, this dream might encourage you to reach out to old friends or reconnect with parts of yourself that you may have set aside.

Overall, this dream can serve as a reminder of the importance of relationships and how they shape our lives.