Memory loss is just one symptom people encounter. Have you noticed your memory is not as it used to be? Do you have a problems losing your wallet, or keys?
Your cognitive performance can also mean tiredness and noticing low energy. Exercise is recommended to keep your energy level up.
LACK OF MOTIVATION
Losing brain power also means lack of motivation. Have you noticed you're not as motivated as you used to be? The brain is where neurotransmitters spark chemical messages to keep us alert and on task. Dopamine is one neurotransmitter that plays a role in the science of motivation and loss of brain power can effect neurotransmitters. Meditating and positive energy can be great tools against lack of motivation.
Losing your focus in another popular symptom of cognitive performance. Whether work or play, you need to keep focused on the task at hand. Some things you can do to keep focus are brain puzzles or games. Keep mental activity up and start reading more to help concentration.