A fast-growing body of evidence suggests that people have difficulties in envisioning how their future selves will look like and behave. So, what determines that one's future self feels like a dissimilar stranger or exactly the same person? Here, we review relevant work and propose a three-factor framework in an effort to organize and highlight important findings. Our review suggests that who we are, what dimension we focus on, as well as the cognitive and affective states we are in, impact the way we envision our future self being similar or different from our current self. We conclude with remaining questions that are yet to be explored.