Two small defaults that compound: caffeine timing and zero processed sweets

Two small rules, both from the same underlying idea: the boundary matters more than the amount.

Delay caffeine until the adenosine flush

The groggy feeling right when you wake up isn't caused by low caffeine — it's adenosine that built up overnight, and your own body starts clearing it within the first 60–90 minutes of being awake and moving. Coffee masks that grogginess by blocking adenosine receptors, but if you drink it the moment you wake up, you're blocking a process that was about to finish on its own, and you push your real afternoon dip later and sharper.

Drink water first, move around, get light. Let the first hour do what it was going to do anyway. Coffee works better as a second-hour tool than a first-minute one.

Zero processed sweets, not "less"

This one seems backwards until you've actually tried it: cutting sweets to zero is easier to sustain than cutting them to "a little." A little keeps the craving-loop alive — you're still making a willpower decision every single time a sweet thing is in front of you. Zero removes the decision entirely. There's no negotiation with a rule that has no exceptions.

The same logic shows up in a lot of habit design: a bright line is cognitively cheaper to hold than a fuzzy budget, because a fuzzy budget asks you to re-litigate the same choice all day.

— Scion Labs