Stanza 3 Summary

Lines 13-14

I have looked upon those brilliant creatures,
And now my heart is sore.

• The speaker says that, having looked at the swans, which he thinks are "brilliant creatures," he is now upset. His heart is "sore." This is kind of like how we say "my heart aches."
• In both cases, this is an example of synecdoche, in which a part is used to describe the whole (the way "all hands on deck" means all sailors on deck, not just their disembodied hands). The speaker describes his heart (a part) to mean that he himself (the whole) is emotionally bummed out.
• The lines imply that the speaker's heart is "sore" because he has looked on the swans. That's odd. How can swans break your heart? Maybe he sees their brilliance and feels he is lacking. Maybe he sees them flying around carefree, and this reminds him of how much he has to worry about.
• It is also possible that he looks at the swans and is reminded of how much different his life is at the moment of the poem's composition, as opposed to the previous nineteen years that he's spent counting them.
• Hmm. That would certainly explain both the twilight and autumn references. Both are indicative of time that has passed (the day or summer). Let's read on…

Lines 15-18

All's changed since I, hearing at twilight,
The first time on this shore,
The bell-beat of their wings above my head,
Trod with a lighter tread.

• The speaker talks more about on his emotional condition. He says that everything is changed since he first visited Coole Parke. 
• Is he talking about the scenery? His own life? The political state of Europe? Maybe he means all of the above.
• These lines get a little tricky, so let's stop for a sec and figure them out. 
• Essentially, the speaker is saying, "Everything has changed," but changed since when? Good question. He recalls when he was first at this place, when he first heard at twilight the beating of the swans' wings above his head. Judging from line 7, we can guess that this was nineteen autumns ago. It looks like that was a time when he "Trod with a lighter tread." In other words, he didn't walk so heavily. He wasn't so downtrodden. In short: those were better days, gang.
• One last note for this stanza: "Bell-beat" refers to the sound of the swans' beating wings. Hmm. Have you ever heard a swan in flight? We're guessing that wings flapping don't sound much like bells. What do bells usually mean though? We're thinking of dinner bells, school bells, etc. Bells here seem to invoke a sense of time. Once again, these beautiful birds remind our speaker of the passage of time.