The chemistry of the brain changes when a person takes a regular intake of caffeine, as it grows more adenosine receptors.

• When we have coffee, it gets absorbed in our gut as well as in our bloodstream. As the chemical is soluble in water and fat both, it can easily enter the brain.
• Adenosine, a molecule present in our brain which is remarkably similar to caffeine,

The good news is that the caffeine habit is easy to break, as your brain sets to baseline levels in about two weeks of caffeine resistance.