[Veto!]

Explains, perhaps, why I can drink 2 cups of coffee a day for that rise-and-shine effect, but a third puts me directly to sleep.

Same with my daughter.

[windcliff]

Me too.

[Ditter]

I never tried that 3rd cup of coffee. I check it out. I have become so sensitive to caffeine that I can't even have any after 1pm or I will stay awake that night till dawn so I doubt that it will have the same effect on me that it has on you.

[TexasKamaAina]

...a third puts me directly to sleep.

The same thing happens to me. Always thought it was weird.