Lessons aren’t learned because you’ve captured them in a “Lessons Learned” section of a post-mortem meeting or report and offered some recommendations that may or may not be implemented in future.
What you’ve done is document lessons to learn, not lessons learned.
For lessons to become learned, they need to be applied.
If you and your team are committed to learning, then go beyond merely capturing lessons to learn and hold yourself accountable to the application of the lessons so they can actually become lessons learned.
Then, from there, keep learning.