A real coffee drink the mental boost is quite noticeable. For some people who cannot notice that, it is either their mental alertness is already at peak capacity so there is no need for coffee, or they are so immune to the effect it no longer does anything to them. Also, at different stage of life you will react to coffee differently due to change in your body metabolism.

Abalone also same right? Even if it claims to have some nutritional benefits which are in dispute, also not worth the price you pay for it. Egg and vege are the best food when it comes to nutrition to cost ratio.