See Bluwave's thread about her h and his 1-2 year OW and return.
If I recall, his was fairly sudden. Though my h acted as if he had not left us, (just checking out a job 2000 miles away...") he did suddenly beg us to join him asap and began calling almost daily and then sometimes more than once daily.
I think once his main task was complete, he looked around and wondered where everyone was...
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016