He already said he does have exercise.

I second this strongly.
I always drink this during my exam days. Extremely good in such that it does increase mental alertness.
If you're rich enough, drink this everyday. I for one am not, so I only drink it during exam days.

I'm like you too, been relying on coffee since 12. Now already 20.
Just recently I've cut down on coffee intake. Only one cup a day, no tea or coffee for the rest of the day.
For the first few days I felt really tired due to lack of coffee. But I forced myself to avoid afternoon naps by exercising during that time. A week after that I definitely feel more awake than with coffee.