And a few lines further:
"That love has arrows, well I knew;
Alas, I find them poisoned too."
For the sake of these last lines, I wandered through the whole poem again and again although I did not care for the rest.
My favourite poem by Keats was:
"I had a dove, and the sweet dove died,
And I have thought it died of grieving.
Oh, what could it grieve for? Its feet were tied
With a silken thread of my own hands' weaving.