This has been my experience in FIR(not that E) as well. I did close tracking from time to time to make sure of our expenses, tried to project future expenses in spreadsheets to make sure our plans were realistic, and, just before retiring, worried about switching from saving to withdrawal mode and how to track things to be sure that spending levels stayed OK. I probably even tried to work out "optimum" levels. :) :)
Like you, we set up portfolio withdrawals (into a monthly "income" account) and as it turns out, we still have a pretty good bead on how we spend without needing any detailed tracking. Basically, we just live our life and the money sorts out just fine. We continue to live on the same annual amount as before, i.e. the amount we lived on after saving 70% of our income when we were working but now we don't need paid work to generate it. Still pinching myself about that last bit.
We do think about money when we're planning something bigger than normal, e.g. a big trip or home renovations, but for daily living, we know what we have and what we need and the money questions have faded into the background.
I think for those who really enjoy tracking and spreadsheeting, losing this as a regular activity might be as big a shock as losing the old 9-5 cubicle time. :) A lot of mental energy and time will be freed up!