Ben Jonson was a very book smart poet and didn't mind showing off his fat brain. As a child he was trained by a famous classical scholar (William Camden), and he was praised by contemporaries for his prodigious learning (straight A's). And by classical we mean all things having to do with those good ol' ancient Greeks and Romans. Most discussions of Jonson's poetry mention something about his love for the classics and the fact that many of his poems contain classical allusions, sometimes very subtle, sometimes not so much.
"To Celia" is a perfect example of this quality of Jonson's writing. Actually, it is almost an exaggeration. If you look at our "Allusions" section, you'll see that Jonson borrowed substantially from a seriously obscure ancient writer named Philostratus, who wrote a series of erotic letters. In fact, nearly every line in the poem echoes or alludes to one of four letters from which Jonson borrowed. Jonson's poem, however, is not just a patchwork of allusions or echoes; he manages to seamlessly weave together ancient sources while also making them his own.