Humans enjoy a singular capacity to imagine events that differ from the “here-and-now.” Recent cognitive neuroscience research has linked such simulation processes to the brain's “default network.” However, extant cognitive theories suggest that perceivers reliably simulate only relatively proximal experiences—those that seem nearby, soon, likely to happen, or relevant to a close other. Here, we test these claims by examining spontaneous engagement of the default network while perceivers consider experiencing events from proximal and distal perspectives. Across manipulations of perspective in four dimensions, two regions of the default network—medial prefrontal cortex and retrosplenial cortex—were more active for proximal than distal events, supporting cognitive accounts that perceivers only richly simulate experiences that seem immediate and that perceivers represent different dimensions of distance similarly. Moreover, stable individual differences in default activity when thinking about distal events correlated with individual variability in an implicit measure of psychological distance, suggesting that perceivers naturally vary in their tendency to simulate far-off or unlikely experiences.