While the general plot of this poem, more or less, is super-famous and not at all difficult to understand, the sheer depth of the symbolism makes it much trickier than you might think. In order to fully appreciate the piece, you've got to be able to recognize references to small bits of Shakespeare, seventeenth-century sermons, and very specific Bible passages. So while a rough grasp of the poem isn't all that difficult at all, truly reading it for all it's worth is no easy feat. Again, that's Eliot at his most Eliot: simple on the outside, insanely allusive and nuanced on the inside. He was never one for cake walks.