Watching the Fujinami matches, it really struck how fast he got good. He wasn't terrible when he showed up in New Japan in 1987, but he was obviously green. By the time he won the IWGP belt in the tournament in 1989, though, he was damn good, and he'd only started in 85.
He was still effective, diminished but dangerous, in his All Japan run, and that gives him 20 years of solid work. Remarkable longevity for a man that size working a rough style.
Update: I'm so stricken by grief that I got mixed up about the difference between 10 and 20. Let's just all pretend it was 20 years.