You are not alone.

Recalling from college neuroscience classes and subsequent reading of research, the studies show the ordinary human sleep cycle when unrestrained adds about a half hour per day, so 24.5 hours is 'natural'. Long-term studies with all time cues carefully removed ended up with subjects on a ~50 hour sleep schedule, as in awake 36-38 hours and sleeping 12-14hrs.

This is also why it is easier to travel across time zones to the west than to the east.