At the beginning of this poem, the narrator seems to be in rather despondent spirits. He is, for one thing, awake at midnight, which he finds "dreary," and he is feeling "weak and weary," yet instead of going to sleep, he is reading a book of "forgotten lore." In the second stanza, he elaborates further on his state of mind. It is December, and the speaker is attempting to find solace in his books to distract him from the tragedy of "lost Lenore." We can assume that Lenore has died because the reference to "angels" suggests that she is now among them.

We do not discover in the poem who Lenore actually is, but it is evident from the narrator's state of mind that he has been very deeply affected by the loss of her. In his attempts to forget the tragedy of Lenore's death, the narrator has been rendered very uncomfortable and uneasy in his mind. He is simultaneously longing for the "morrow" to come, and reluctant to actually go to sleep and give up on the evening. His mental discomfort has led to a disruption in his schedule, which is how he comes to hear the tapping at his door at this time of night.

It seems as if he is grieving, trying to forget a loss of a person. His mental state seems to be in that place between sleep and wakefulness as he lets us know it is late at night, he is nodding, and nearly napping and it seems he's into a book (one of the best ways many of us fall asleep). He is in front of a fire, likely very warm, and his body quite comfortable in an easy chair although his mind is not at all at ease.

You mention the beginning of the poem. The whole poem is certainly about trying to forget someone who has passed, but the beginning does use the word "forgotten" in reference to lore. Lore means ancient literature or books. He may have been reading something that many have forgotten. His intention in reading was to help him forget his sorrow, sorrow for the loss of someone named Lenore.