In summary, the consumption of caffeine can have varying effects on individuals and the amount needed to produce these effects can differ from person to person.
Actually, as a scientist, I have found that the effects of caffeine on individuals can vary greatly. Some people may experience increased alertness and energy from consuming caffeine, while others may not feel any difference at all. Additionally, the amount of caffeine needed to produce these effects can also vary from person to person. So while I do drink a lot of coffee, it may not necessarily keep me awake in the same way it may for someone else. However, I have found that it does help me stay focused and productive during my workday.