You know what to do but you don’t do it.
For most of my life, I slept really well. Lay day, fall asleep, wake up 7 or 8 hours later. When my son was an infant/toddler, I could even go back to sleep after getting up in the middle of the night (much to his mother’s consternation).
But, as I’ve gotten older, it’s gotten harder. In particular, any kind of alcohol messes up my sleep. 2 glasses of wine with dinner and I’m up at 2AM for two hours. So, I’ve cut out alcohol. And I will say that I miss my Sancerre.
But even after I accepted that alcohol was messing with my sleep, it took months, even years, until I finally cut it out. Partially, because the up in the middle of night time periods where getting longer. And partially because all those problems I liked to tune out from with those few glasses were coming roaring back in the middle of the night.
It’s not what you know. It’s what you do with what you know.