While large language models (LLMs) showcase unprecedented capabilities, they also exhibit certain inherent limitations when facing seemingly trivial tasks. A prime example is the recently debated "reversal curse", which surfaces when models, having been trained on the fact "A is B", struggle to generalize this knowledge to infer that "B is A".In this paper, we examine the manifestation of the reversal curse across various tasks and delve into both the generalization abilities and the problem-solving mechanisms of LLMs. This investigation leads to a series of significant insights:(1) LLMs are able to generalize to "B is A" when both A and B are presented in the context as in the case of a multiple-choice question.(2) This generalization ability is highly correlated to the structure of the fact "A is B" in the training documents.(3) We propose and verify the hypothesis that LLMs possess an inherent bias in fact recalling during knowledge application, which explains and underscores the importance of the document structure to successful learning.(4) The negative impact of this bias on the downstream performance of LLMs can hardly be mitigated through training alone.Based on these findings, our work not only presents a novel perspective from LLMs' intrinsic working mechanism for interpreting their generalization abilities but also provides new insights for the development of more effective learning methods for LLMs.