Many moons ago I got very, very drunk on wine one night and ended up ripping my throat on the upchuck.
The next day I, unsurprisingly, felt decidedly rough. As the day went on I got headaches, tight shoulders, aching neck. The next day it wasn’t getting any better.
The following day I still felt rough, never had a two hangover before. However the fog had somewhat cleared from my mind and I reaslised in the evening (I mentioned the torn throat earlier) that I hadn’t had any tea or coffee for over 48 hours (normally I was having a coffee pretty much every hour). Deciding that it might be something to do with it I made myself a caffetierre of proper coffee. By the time the first mug was drunk ALL my symthoms had disappeared…
I now limit myself to 3 coffees a day (ok sometimes I push the boat out and have 4) and highly unusual to have one after 6 pm. Its kind of amazing how it can creep up on you!