Bright Star, would I were stedfast as thou art— Not in lone splendor hung aloft the night (lines 1-2)
One of the most striking things in Keats's poem is the turn from line 1 to line 2. How can you go from saying you want to be like something one moment and then saying that you don't want to be like it the next? Well, as it turns out, you very well can – if there is some part of the thing you admire and want to be like, but another part of it that you don't admire and don't want to be like. The second line of the poem begins to make clear what it is about the star that isn't Keats's speaker's cup of tea. What is it? You got it – the isolation of the star. Sure, he says it has "splendor," but look at all the other words that convey a negative message: "lone," "hung aloft" (i.e., at the highest point and therefore separated from everything else), and "night," which is a time of darkness and coldness. This seems pretty clear in getting the point across, doesn't it?
Like nature's patient, sleepless Eremite (line 4)
The theme of isolation continues in this simile from line 4. This time, the speaker even puts a name to the concept, by calling the star an "Eremite." What the heck is an "Eremite"? It's just an old-fashioned way of spelling "hermit." A hermit is a person who goes to live in a deserted place away from everyone else. In fact, the old-fashioned spelling Keats uses here actually helps to emphasize the sense of isolation. That's because the word "hermit" originally comes from the Greek word "eremia," which means desert. (The first hermits lived in the desert to be closer to God.) The earlier spelling of "hermit," "eremite," makes the connection to the root meaning a bit clearer. Also, the fact that Keats capitalizes the word and singles it out with the words "nature's patient, sleepless" might make the star seem even more isolated. At least that's what we think these words might be doing here. Any other ideas?
The moving waters at their priestlike task Of pure ablution round earth's human shores (lines 5-6)
Now, you might say after reading these lines, "Hey, where's the isolation in that? Look: the waves are moving around the earth, they're keeping the earth company, what's the problem?" Well, we wouldn't disagree with you. The waves sure look like they're keeping the earth company – but are they friends to humans? The wording doesn't make it totally clear, but we don't think it would be crazy to say that the waves are, in fact, purifying the earth of humanity, and so don't like humans very much at all. Because this scene is so far removed from the things ordinary people care about, we think the speaker would find it all a bit chilly, isolated, and off-putting. After all, as we learn at the end of the poem, the speaker definitely cares about love, personal connection, and all the normal things that people care about.