Research has shown that bilingual individuals might encode autobiographical memories in either their first language (L1) or their second language (L2), depending on the language spoken at the time of the event. Although language mixing is a common occurrence among multilingual speakers, previous studies have largely overlooked mixed memories -- those encoded in both L1 and L2. The current study aims to bridge this research gap by analyzing a corpus of 1,297 memories (636 L1 memories, 357 L2 memories, and 305 mixed memories), with a particular focus on memory phenomenology, including factors such as vividness, emotional arousal, and personal significance. The statistical analysis revealed that mixed memories exhibited higher levels of emotional arousal and personal significance compared to memories encoded exclusively in L1 or L2. These findings underscore the unique status of mixed memories in the bilingual mind and emphasize the importance of adopting a heteroglossic approach to the study of bilingual autobiographical memory.