True. Then again, his son wound up captaining the Enterprise for a similar period.
Nope. James T Kirk became Captain of the Enterprise in 2265. He had his 5-year mission, became super-famous, and was promoted to Rear-Admiral, posted as Chief of Starfleet Operations, in 2270. He recommends Will Decker to become his replacement. V'ger shows up in the mid 2270s (Star Trek: The Motion Picture). Kirk reassumes command of the Enterprise in the mid-to-late 2270s, but then retires. He eventually returns to the Admiralty to suppervise Command track cadets in 2284, and then steals the Enterprise to deal with Khan (Star Trek II).