This research full paper explores interview data with N=36 engineering graduate students to understand the factors and characteristics of graduate socialization, with the effort of better preparing students to succeed in doctoral programs. This research is motivated by the alarming fact that nearly one-third of engineering doctoral students will not finish their PhD programs; however, little research has been conducted on the various factors that can lead to attrition or enhance persistence in graduate engineering programs. This paper presents the results from the interview phase of a larger study investigating doctoral engineering socialization, attrition, persistence, and career trajectories. The participants for this study come from large research-intensive universities across the United States, and were sampled for maximum variation in a number of different categories, including stage in their doctoral program, gender, and race. Upon collecting and analyzing interview data from our participants through constant comparative and content analysis methods, several themes arose including concerns for mental health in engineering graduate students and uncertainties with joining the culture of academia in their future careers. Further, although the participants for this study are currently graduate students who anticipate completing their PhDs, nearly half of the participants discussed strongly considered leaving at some point. This study adds to the body of literature surrounding engineering attrition and the underlying issues driving engineering PhDs away from academic engineering careers.