Ananda said to the Buddha: "I think there has never been a teacher as great as you, nor will there ever be one as great in the future."

The Buddha asked: " Have you known all the awakened ones, the Buddhas of the past ?"
"No, Honored One."
"And are you able to know all the Buddhas of the future?"
"No, Honored One"
"Then I suppose you do know this awakened one's mind completely?"
"No, Honored One, I do not even know your mind completely."
"Then how can you make such a bold statement? It is better to talk of what you know than to speculate foolishly."

( Majjhima Nikaya )