Star Trek: Picard's second season has been about unpacking the long-buried trauma in Jean-Luc Picard. This trauma has prevented him from getting close to the people he loves. The season has hinted that it has to do with Picard's mother, Yvette. The series has shown glimpses of Yvette being dragged away from Jean-Luc throughout the season. A previous episode revealed that this was Picard's father, Maurice (played by James Callis). Maurice had been restraining Yvette when her mental state may have led her to harm herself or Jean-Luc. But, as that episode implied, that wasn't the story's entirety. The season's penultimate episode, "Hide and Seek," reveals the story's tragic ending. SPOILERS follow.
Previously, the flashback to Picard's childhood ended with his mother locked inside a room and him standing on the other side of the door. "Hide and Seek" reveals that young Picard used a skeleton key to unlock the door at his mother's request. As a child, Picard didn't understand his mother's illness and thought his father was simply being cruel. In truth, he was trying to protect Yvette from herself. After Jean-Luc falls asleep next to her, Yvette gets up and goes to the atrium to hang herself.
Afterward, young Picard throws a rock through the atrium's glass window. These events explain why Picard allows the atrium to remain in disrepair even after restoring the rest of the château. Blaming himself for her death, Picard buried the memory of his mother's suicide. He notes that he sometimes imagined her growing old and sharing tea with him. (This explains the vision Picard has of his mother as an older woman in the Star Trek: The Next Generation episode "Where No One Has Gone Before."). Picard escaped to the stars via Starfleet, and the deep fear of experiencing the pain he experienced at the loss of his mother has prevented him from fully loving anyone ever since.
While Picard finally recalls the truth of his mother's fate in "Hide and Seek," he still blames himself for what happened. With one more episode of the season to go, fans will have to wait and see if he can find a way to heal from the trauma.