We examined free recall and metacognitive judgments of ambiguous sentences studied with and without clues to facilitate their comprehension. Sentences were either studied without clues, with clues meaningfully embedded, or with clues following a 10-s interval delay. After presentation, subjects made judgments of comprehension (JCOMPs) or judgments of learning (JOLs). Puzzling over the meaning of sentences for several seconds prior to receiving the clue enhanced recall compared with studying sentences without clues or with embedded clues. This benefit of effort after meaning was not reflected in JCOMPs or JOLs. Rather, sentences considered relatively easy to understand received higher JOLs regardless of experimental condition. Although effort after meaning enhanced recall, subjects displayed no awareness of this benefit in their judgments. Our study adds to a growing literature showing students' ignorance of factors affecting their own learning, which have important implications for education. Making learning conditions more difficult, thus requiring students to engage more cognitive effort, often leads to enhanced retention. (Contains 2 tables and 2 footnotes.)