adamgluck

  - Less anxiety throughout the day.
  - Fewer "highs" and "lows" throughout the day. My energy level is pretty constant.
  - Easier to wake up. I rarely snooze my alarm more than once.
  - Easier to focus. My level of focus (over time) is more consistent.
  - Better hydration. This means less headaches, etc.
  - More energy. I generally have the energy I need to do what I want basically up until I go to sleep.
  - I can burn sleep. It's very easy for me now to go 2-3 days with very limited sleep, and then sleep 12 hours to recover.
  - Coffee "works." The one or two times I needed coffee, it actually worked to keep me awake and energized.

  - You will get a headache 24-36 hours after you quit. Take ibuprofen. (By the way, this should give you a hint to how long coffee actually meaningfully stays in your system.)
  - You will feel weird for probably 2 weeks.
  - You will have coffee cravings. (I found these hit when I was tired. I felt like I needed to drink coffee to fix my tiredness. I tried to replace this impulse with drinking water or herbal tea a lot of tiredness is caused by dehydration.)
  - You will be tired sometimes. You'll just have to deal with that, but it's really not that bad of a sensation, and the solution: sleep :)