Are you not getting much sunlight? I can understand the reaction to being told something that doesn’t match your experience. But. The link between sunlight and sleep for most life on earth is pretty well established science, and has a name: Circadian Rhythm.
Have you ever tried camping for a week? My sleep tends to drift when I’m working indoors a lot, up late at night a lot, during winter, etc. But if I spend multiple days outside, it starts to align with sunrise almost immediately.
Both of these links say that Circadian Rhythms tend to drift and be longer than a day on average in the absence of sunlight.
