You will miss your work colleagues at first but rest assured that loss wears off -just recall what they are still having to put up with while you are lounging ,resting, and deciding how you are going to occupy your day -bliss.
Whenever I drive past the building where my former colleagues still slave daily - I always say 'poor sods'
Even though I retired early at age 51, family committments (granny duties and needs of an aged parent) kept me over occupied for the first 5 or 6 years of my (so called) retirement.
After that I did feel that I was no longer a useful member of society.
That 'guilt' wears off too
