In this sonnet, the speaker talks about the sorrow and grief that he feels when he considers all the people and things he has lost in his life. He cries when he remembers his good friends who have passed away, he weeps when he recalls lost loves that have come and gone, and he wails when he considers all the scenes he has witnessed that he can see no more. After this, he even grieves over losses he has already come to terms with and grieves them all over again, as though he never had actually grieved them. He uses a metaphor here, comparing this last kind of grieving to an "account" that he must "new pay as if not paid before"; in other words, he has already grieved (or "paid") and yet he feels as if he must grieve all over again (paying this "account" again, when he already feels he has paid).

William Shakespeare's "Sonnet 30" is about the speaker feeling dejected when remembering past woes and losses. For example, in the first two quatrains, he "drowns an eye" remembering "precious friends" who have passed away, and he wastes his time thinking about "old woes." However, his sorrows end when he thinks of his "dear friend" in the couplet, and all of his losses are restored.

Essentially, the speaker of "Sonnet 30" is recalling sad events in his past, and feels the pain over and over again. In the third quatrain, the "sad account" in line 11 is equivalent to an itemized bill requiring payment. This metaphor refers to the speaker's sorrows that never seem to go away but keep plaguing him, just like a bill that has already been paid but continues to demand payment. This means that the speaker must suffer these "fore-bemoaned moans" continuously even though they are in the past and he has already mourned them.

Lucky for him, he has a friend to cheer him up.