Life is as habit-forming as cocaine.
-- C.S. Lewis, Surprised by Joy
On the face of it, that is a zinger, of no very clear meaning, jejune and shallow. From the pen of an Oscar Wilde, it would have been exactly that.
In fact, it is a serious statement, only incidentally somewhat epigrammatic. It occurs during Lewis’s discussion of G.K.C.’s Manalive (the scene about dangling the God-mocker out the window). It is one step in a complex argument which I shall not attempt to summarize. It is thus an anti-epigram (the antiparticle of an epigram): whereas an epigram, for what it’s worth, survives its loss of context, seeking only to glitter, CSL’s observation is rigorously contextual.