I spent 25 years feeling tired all of the time. Chronic night owl, I would find that my most productive periods would come precisely when I was "supposed" to go to sleep. I could either lay in bed, wide awake and frustrated, or end up destroyed the next day, which was basically every day. I'd try to catch up on weekends, but you'll find plenty online about how poorly this actually works.
What changed is that I noticed how, left to my own devices without external schedule pressure, I would naturally drift 3h forward every day - and so I realized I had the opportunity to actually fully go with the schedule my body seemed to want to have. I informed my family what I intended to do, cleared my calendar for the next week, and went for it.
First observation: my biggest hesitation was social judgement. I was consciously aware of how little I wanted people to think I was a weird dude.
Well, turns out I'd rather be weird and feel great than normal and feel like a zombie. My body almost immediately seemed to breathe a sigh of relief and six months later, this part of my life is amazing.
I find it endlessly curious how some people seem seriously distraught when I tell them what I've been up to. Not because they have any medical opinion, but because it appears to challenge something that clearly gives them a feeling of being normal.
My doctor actually had very little to say, once they heard me out and read the research I gave them. Essentially, "please stop if you start feeling bad".