To recap: Three days ago I slept extremely well, better than usual. I wondered why. What had made the difference? That day (the day before the night I slept so well) had been different from previous days in at least five ways (e.g., chocolate, new brand of honey). I repeated four of them, and did not sleep better than usual. That suggested the remaining difference — I had eaten yogurt, blueberries (125 g) and honey (8 g?) a few hours before bedtime — was responsible. (Every night I had 1 tablespoon — 20 g — honey at bedtime. It wasn’t that.) Then I repeated all five elements, including yogurt, blueberries (125 g) and honey (14 g) two hours before bedtime. I woke up wired (jittery). Very rested, but wired, which wasn’t pleasant. Too much sugar, perhaps.
The next night I had a banana roughly two hours before bedtime. (In addition, I repeat, to 1 tablespoon honey at bedtime.) A banana has about 6 g glucose, 6 g fructose, and 3 g sucrose, similar to 1 tablespoon honey. I had a strong craving for something sweet at that time, which was new to me — I almost never eat dessert. In the evening I had more brain power than usual. Yet at bedtime I fell asleep quickly, in about a minute.
The next morning I woke up and felt great. Almost perfectly rested, neither tired nor wired. Even though I’d only slept 4.7 hours, a bit low for me. It really was the yogurt, blueberries and honey — almost surely their sugar, which is almost all they have in common with a banana — that had made me sleep so well.
Conclusion: For the best sleep, have sugar after dinner and sugar at bedtime. By sugar I mean a glucose/fructose mixture but for all I know sucrose would work, too.