In our courses we benefit from the wisdom and sharing in the group. It is important to be aware that mindfulness is not therapy. While people are invited to share and exchange, there is no going back to childhood memories or traumas. Mindfulness is about the experience in the here and now, how habits and patterns (from the past) come into play in today's doing and thinking, and how we can work with them by bringing mindful awareness to it. Therapy is usually precisely about finding the roots, going back to the triggers and finding a way to heal.
In the sharing in the groups we have noticed that people enjoy learning from each other and discovering that they are not alone in their struggles of everyday life. It is also very powerful to meditate in a group setting. See here a video for more explanations.