Courtney,
The presence of Ross Geller, a fictional character from the series "Friends," in your dream suggests a connection to familiar themes of friendship, comfort, and perhaps nostalgia. Playing computer games with him might symbolize a desire for relaxation and a break from your reality, where such activities are associated with camaraderie and leisure. The moment of peace you experienced reflects an inner need for tranquility and the enjoyment you find in shared hobbies.
However, the shift in your emotions from peace to sorrow upon realizing Ross is not Meredith indicates a deeper longing for a specific kind of companionship that you've treasured in the past. Gaming with Meredith likely represents a significant bond and a sense of understanding that you miss. The sadness in realizing the person beside you isn't who you expected could be a manifestation of a feeling of loss or change in your waking life relationships.
The sorrow connected with this substitution might be highlighting feelings of disappointment or the fear of losing touch with someone important to you. It's essential to reflect on current relationships and whether there's an underlying concern that needs to be addressed. While the dream did not have a high intensity of negative emotions, and it wasn't a nightmare, it did carry a note of sadness, which is worth acknowledging as it may point to a subtle emotional process occurring within you.
Your dream seems to be a gentle nudge to examine your current social connections and perhaps a prompt to reach out or reconnect with those who share your interests and with whom you feel at peace. It appears to be less about the actual gaming and more about the companionship and the shared experiences that bring comfort to your life.