Why is it important for us to reflect occasionally?

There are countless of occasions where I stop and reflect on what I have been doing for the past few days or week. This was a habit that I have built since I started working. I had to gauge my progress in order to plan ahead (as I was very far behind compared to my peers) and start moving forward steadily. My starting point was just discriminatory (i.e., perhaps, I will write about this some time in future). Reflecting was the only way and tool for me to review my work, progress and improve.
Without reflection, I probably would be just doing and redoing the tasks that have been assigned by bosses without active thinking on my part. As time pass, I tend to get into “auto pilot” where I finish a simple and straightforward task within minutes as I had become so familiar with the “steps” to complete the task. Some may think that it is beneficial for the company because you have become “competent” at your job. Others may see this as an increase in productivity as one gains more experience. To me, this means that I have become “complacent”. Being in “auto pilot” mode, I am no longer actively thinking about the tasks from perspectives that I might not consider. The potential dependencies which need to be considered and the unrealized blind spots that I have not put in effort spot them out.
By intentionally setting aside some time for reflect (at least once a week), it allows me time to think about the work that I have done, assess how well I have done them, and think about the improvements that I could make in the upcoming weeks. A word of caution: Reflection could also be a trigger for change (be it a job change or a lifestyle change) as it is one of the key ingredient in continuous improvement. And when that happens, are you prepared for the change?