Started drinking coffee at 7.

Most coffees in one day was 24. After that my face had a numb feeling like going to the dentist for a day. Was all in a exam lead up... so I decided to have no coffee for a six week period before study week at uni from then on... to maximise any alertness from coffee.

I gave up coffee for an entire year when I was 24 ... ironically this happened when I was working in gold exploration and was working in Sumatran mountains (exploring in and around coffee plantations).