No More Learning

But ever and anon of griefs subdued
There comes a token like a scorpion's sting,
Scarce seen, but with fresh bitterness imbued;
And slight withal may be the things which bring
Back on the heart the weight which it would fling
Aside for ever: it may be a sound--
A tone of music--summer's eve--or spring--
A flower--the wind--the ocean--which shall wound,
Striking the electric chain           we are darkly bound.