Since Esoteric Buddism was the state-of-the-art Buddism at the time, Saicho was very curious and serious about learning what it is.
So, he visited Kukai, the best of the best in that field and asked him to teach him Esoteric Buddism.
Kukai said, “If you are ready to give up your current status until you master Esoteric Buddism here as an apprentice monk, I’m more than welcome to.”
Since Saicho at the time already had established his school to teach Buddhism and had very important jobs and socially responsible positions, this condition was totally unacceptable for him.
Therefore, he gave up learning Esoteric Buddism.
Hearing this unhappy end episode, disappointingly shallow people would say, “Kukai is stubborn and mean.” or “He’s gotta be merely jealous of Saicho who happened to be an excellent student and well-treated by the dynasty.”
To truly learn something, one has to commit himself for a certain period of time and to see it for oneself through actually experiencing it.