WOW, I missed the beginning of this thread ..... and it's on page two already!
Congratulations on your retirement. You will not miss the hectic pace very long ..... trust me!
I retired from teaching nine years ago, as soon as I was eligible ..... like you, I retired before I burned out ..... and because I was spending more time writing lesson plans and documenting what I had done than I was hands-on with the students. Actually my first year of retirement was spent doing a half-time job counseling at-risk gifted high school students so I had a chance to step down a little bit more gradually.
It does take awhile to "de-structure" one's life after the early morning to late night routine for so long. However, what I know from you on this forum, you will most likely have to keep repeating the phrase "No, I cannot do _____, I'm retired."
Best wishes for a great retirement!
Clarice