Retrospectives trump Planning

I was in a CMMI adoption process meeting today and I might have argued that the Scrum Retrospective activity (process step) is more important than the Scrum Planning activity.  Yet, know-one took the bait.  What would be a better piece of bait?

We were discussing what process steps we should define to meet CMMI something something... and the list on the board look like:

• Sprint planning
• backlog grooming
• release planning
• project planning
• risk mitigation planning

[note - only one is a Scrum activity]

I was trying to point out that as a subset of Scrum practices this list is interesting, yet not sufficient.

I believe that planning is way less important that the activity of reflection (learning).  I could refer you to some wonderful quotes by US Army Generals about the uselessness of plans.  But let me skip that meme and jump to the assertion that Retrospectives are more important that planning activities.

WHY?

Because with just that one practice, Retrospectives, a team that was doing no planning could derive a practice of planning using the practice of reflection and adaptions (learning).  Therefore Retrospectives trump Planning every time.

I find it interesting that we were focused on the secondary practice.  Does CMMI have a learning practice defined?