The poet's pleasure in it is full but undiscriminating; he makes no attempt to put the 'something' the birds 'knew' into words.
Who knew thee once, we have a right to weep.
She had profound thoughts, and she knew the night was temporary.
While impermanence was not a reality they knew, he became embittered.
He knew, for one thing, what he was.
He knew where he wanted to go, and in domestic affairs as well as foreign he accomplished most of his purposes.
He knew he had far more anecdotes, recorded conversations, letters - more were coming in all the time - insight, and sensitivity than his rivals.
He knew there were plenty of envious and hostile readers out there waiting for him to take a false step.