This is the sonnet that begins "Shall I compare thee to a summer’s day?" After that opening, you think it’s going to be a love song, but it doesn’t really turn out that way. It’s more a matter of "Don’t worry that you are going to get old and die: I’ve written this brilliant poetry about you, and your fame will last forever". A little ironic, considering that no-one knows the identity of the woman they were addressed to, or even whether it was a woman at all. It could have been a man, since the sonnets are dedicated "To Mr W.H."