This guy has been through the wringer with love, and emerged with a clearer understanding of it. He’s absolutely certain that the vision of love he depicts here is the right one, and he’s willing to stake his reputation as a poet on it. We get the feeling that the Speaker has experienced what he thinks of as "the marriage of true minds," also known as true love, that his love remains strong, and that he believes that it’s eternal. What with all the ships and stars and stormy seas that fill the landscape of the poem, we imagine him in full-on, rather melodramatic Elizabethan poet mode, gazing out to sea with fiery eyes half-hidden beneath a floppy, feather-bedecked velvet hat, cursing fate and vowing his undying love to some distant lover…something along the lines of the end of Shakespeare in Love. You get the picture. We suspect that he’s been there and done that, and is now relating what he’s learned from life to a younger listener.
However, before you give us all the credit for this brilliant analysis, we should come clean: this isn’t just our interpretation of the Speaker (well, except for the floppy hat). Actually, it’s a common view of the relationship between Poet and addressee. In Shakespearean circles, there’s a general consensus on the appearance of several figures in the sequence of sonnets. They aren’t exactly characters, which is why this info doesn’t appear in the "Characters" section. They’re more like the ideas of people, rather than actual people.
The first is the Poet, identified as Shakespeare, but not necessarily directly aligned with him (the poems may or may not be autobiographical). The next figure that we see is the so-called "Fair Youth," the subject of Sonnets 1-126. These sonnets are addressed to a young man, whose relationship to the Poet is somewhat unclear; some people read these sonnets as expressions of platonic love and affection, while others have questioned whether or not there are clues to a gay relationship here. FYI, the two final figures, who don’t relate to our discussion of Sonnet 116, are the "Dark Lady," a mistress of the Poet’s (Sonnets 127-154), and the "Rival Poet," who appears in Sonnets 78-86.