What electromagnet is still keeping me running (8)
So we've got, at first glance, a continuation of the central heating and technology metaphors in this poem—obviously, humans don't run on electromagnets, machines do. But what interests us, in terms of the theme of dissatisfaction, is the word "still." The use of this word makes us think that, for the speaker, it's beyond all hope that he's still alive, still working.
My eyes and my love are both taking the same wrong road (9)
Our poor speaker is in love, but he's not even satisfied with his love. He feels that his love and his eyes (which, we're guessing, are looking at the object of his love) are all wrong. We don't know why this is, but either way, the speaker is dissatisfied with love, one thing that, for all the pain it can cause, many people find fulfilling.
A mere nothing (10)
Not only does our speaker feel dissatisfied, he has an overbearing sense of nothingness. It's not a very fun thing to think of yourself, or anything you may find important as, well, nothingness. We don't exactly know what he's talking about here in particular, which adds to the sense of generalized dissatisfaction. Everything could really be merely nothing, this line leaves it open to say.
I've had enough of the wind I've had enough of the sky (12-13)
Again, we see our speaker being just plain dissatisfied. We don't know what's wrong with the wind and the sky—it's not as if our speaker has had enough of rain and clouds, which it would make sense to be sick of. No, he's sick of the wind and sky in general, including gentle breezes on warm day, and the sun poking through after storms. He's not open to happiness, and writes off the wind and sky as parts of the world he's sick of.
The door is wide open but I refuse to enter (17)
This line shows us that our speaker is very well aware that his problems are in his own attitude. Open doors normally symbolize good things—new opportunities, ideas, enlightenment, growth. The speaker knows that all this is available for him, but he's so dissatisfied with where he is now, and where he thinks that open door will take him, that he refuses to walk through it.
One night when we were unhappy we sat down together on a trunk (20)
The speaker is even unhappy when he's with his lover. Yet the funny thing is that he brings up this memory only to lead himself to the last line of this poem, which reflects on his lover quite fondly. Perhaps dissatisfaction is the speaker's preferred state. He relishes the kind of unhappiness he has when he is together with his lover, sitting on a trunk, watching the world go by with sadness in his eyes. Yeah, sounds like a blast to us, too.