I have earned three retirements. One by default, one by stupidity (I was at my dream job, looked up too, moved as high in the organization as my education level would let me and could take a big bonus if I stayed two more years yes I WAS S T U P I D!) Left it because I thought an opportunity was open that might never come again. Boy was I stupid. Five new hires in that last job on the year I was hired, within three years, all but one of us had left, that one was Mr. Stupid here. Finally left the last because i was really ready. Loved by some, hated by others and never really able to please anyone no matter how hard I tried or what I accomplished.
However, there is real truth and best advice, never ever talk down your boss or your former job after leaving. Makes it hard to move on as you simply won’t be trusted (not to trash your prospective new employer when you leave)