It means you can't pay attention.
The word concentrate in essence means to draw or focus towards a common centre. It can however be used in a number of ways in its noun and verb forms.
As a noun it can be used to refer to a mineral that is recovered after all impurities are removed from the ore, in other words when the ore is refined.
Concentrate also means a concentrated form of food product. It is formed after excess water is removed. The most common application is in fruit juices. Most of the fruit juices available today are diluted forms of fruit juice concentrate.
As a verb concentrate is used in a similar sense as the above to make something concentrated. It is used also when referring to the thought process of the mind. A person has to concentrate his thoughts to grasp a topic being taught better. It can be used to mean bringing things together, centralising them and even to cooking when doing so with an aim to boil away the water.
As a noun it can be used to refer to a mineral that is recovered after all impurities are removed from the ore, in other words when the ore is refined.
Concentrate also means a concentrated form of food product. It is formed after excess water is removed. The most common application is in fruit juices. Most of the fruit juices available today are diluted forms of fruit juice concentrate.
As a verb concentrate is used in a similar sense as the above to make something concentrated. It is used also when referring to the thought process of the mind. A person has to concentrate his thoughts to grasp a topic being taught better. It can be used to mean bringing things together, centralising them and even to cooking when doing so with an aim to boil away the water.