Why did Derek choose Addison in the first place? It was clear that he still had feelings for Meredith.

Derek’s choice to be with Addison in the beginning of Grey’s Anatomy can be attributed to several factors:

1. History and Commitment: Derek and Addison had a long history together, having been married for several years before the events of the show. Their relationship was built on shared experiences and a deep bond, which made it difficult for Derek to completely let go of that commitment, even as he developed feelings for Meredith.
2. Guilt and Responsibility: Derek felt a sense of responsibility toward Addison, especially after their tumultuous separation. He was grappling with guilt over their marriage’s issues, which influenced his decision to give their relationship another chance when Addison arrived in Seattle.
3. Uncertainty with Meredith: At the start of the series, Derek was still navigating his feelings for Meredith. Although he was drawn to her, he was also confused and conflicted about the nature of their connection. Choosing Addison was, in part, an attempt to stabilize his life and avoid the chaos of his feelings for Meredith.
4. Desire for Normalcy: After returning to Seattle, Derek sought a sense of normalcy and familiarity, which he believed he could find with Addison. He was in a transitional phase, and being with someone from his past provided a sense of comfort.

Ultimately, Derek’s feelings for Meredith grew stronger over time, leading to significant tension and drama in the series as he struggled between his past with Addison and his evolving relationship with Meredith.