Well, as a new years resolution I decided to go without coffee or caffeinated drinks. It is now just about a month without caffeine, or at least with nothing like the dose previously consumed.
I am not sure what effect this has had on my mathematics.
Paul Erdös once remarked “in Hungary many mathematicians drink strong coffee”.
Alfréd Rényi stated “a mathematician is a machine which turns coffee into theorems”.
So, I think we can claim a link between coffee and mathematics!
Anyhow, as of February I will be doing more mathematics in coffee houses.