It was all a bit surreal. I knew what was coming, but no one else did. It was exciting but scary, and I had many moments of doubt, regret, guilt, giddiness... pick an emotion. To make matters worse, I had recently allowed myself to be talked into a new role, and was trying my best to play the part of my earlier mover/shaker self. Yet, large parts of my workday were spent reading intranet sites about my pension, stock options, retiree health insurance, etc.
After I finally let my boss in on the plan, we had a "quiet period" for about a month while my replacement was chosen. That was a fairly awkward period, with several visits from SVPs, HR, et al, to find out what was "really" going on and "fix it." After it finally went public, I felt overwhelming relief. All pressure was instantly gone. I cleared my calendar and spent two days answering really nice emails from people I had worked with over 25 years.
I ended up staying on for 4 more months. I worked a special project, helped my replacement get oriented to the new role, and used up my remaining vacation balance the rest of the time. Yeah... surreal is the best word. By the time I finally turned in my badge, it was a non-event. I had already mastered the art of piddling around the house and there was no going back.