It is mind that is one of the most important factors for efficiency working in life. If you have clear mind, you may work well than when you are in bad mood. There are several cause that can make your mind unclear mind or can not concentrate, including anger, indolence and anxiety which can cause inefficiency for your work.
One cause of unclear mind is the anger. If you are angry someone or in a bad mood, it normally makes your mind unclear from this bad feeling. Also you may not do well in your work like when you are happy or in normal feeling and your friends might feel uncomfortable with your anger. For example, when I was angry, my mind couldn't concentrate with my studying and everybody around me felt unhappy. The Anger also make you feel like you are in fire, and it contribute unhappiness to you.
Another cause is the indolence or laziness. If you feel lazy because you want to sleep or your work is boring, your mind usually cannot be concentrate like you don't have energy to do your work. For instance, I always felt sleepy when my classes were boring or I had not slept enough, so I couldn't concentrate in studying, and it caused me low grade. The indolence makes you feel like you have no energy or cannot focus on your work, including falling asleep and boring.
Finally, the anxiety also can make your mind unclear. If you feel nervous or worried by something, your mind cannot absolutely focus on what you are doing and may cause unappreciated result. For example, in sport games, the sport player who are worried about other thing but their games may not show their best ability in game and it can causes them lose their games. The anxiety can confuse you mind from your work of what you are doing .
The unclear mind which is caused by the anger, indolence and anxiety can contribute not only inefficiency but also sadness to you life. Many people believe that mind is more important than body, and they try to make their mind clear for good performance work and happiness life.