The present study employed a think-aloud method to explore the origin of a centrality deficit (i.e., poor recall of central ideas) found in poor comprehenders (PC). Moreover, utilizing the diverse think-aloud responses, we examined the overall quality of text processing employed by PC during reading, in order to shed more light on the cognitive underpinnings underlying their poor comprehension and memory after reading. To address these goals, adolescents with good and poor comprehension, matched on reading (decoding) skills, were asked to state aloud whatever comes to their mind during the reading of two expository texts. After reading, the participants freely recalled text ideas and answered multiple-choice questions on the texts. Results indicated that PC exhibited lower performance than good comprehenders (GC) on the recall and comprehension tasks. The think-aloud protocols indicated that PC generated fewer responses than GC that reflect high-level, deep text processing, and more responses that reflect low-level, surface text processing. Furthermore, compared to GC, PC reinstated fewer prior text ideas, with this reduction being significantly greater for central than for peripheral ideas. Finally, the proportions of deep processing responses in general were positively associated with participants’ performance on recall and comprehension tasks. These findings suggest that PC exhibit poor text comprehension and memory, particularly of central ideas, because they construct a low-quality, poorly-connected text representation during reading, and produce fewer, less-elaborated retrieval cues for subsequent text comprehension and memory. This explanation is further illuminated in the context of previous findings and theoretical accounts.