Is a retreat still necessary if you can already quiet your mind in daily life?

Being able to settle yourself in daily life and having further lessons to learn on this occasion are different matters. Whether to undertake retreat still depends on what you hope to learn and need to face at that time. Greater ease with stillness does not mean there can be no new benefit. Different purposes may lead to different insights.

I once thought this way myself: after years of practice and regular meditation and exercises, quieting my mind had become easier, so perhaps I no longer needed retreat. Yet in a later retreat, reflecting on spiritual practice, my mission, and how to teach brought new insights. Time spent in retreat does not need a dream of divine instruction to be useful.

Looking back, I therefore consider whether my understanding and inner thoughts have moved forward. Sometimes you know roughly what direction the practice will take beforehand, yet cannot prescribe exactly where or how much progress must occur. First understand what you are to learn on that occasion, then actually do it. This is what I came to understand through that experience.