This will all depend on the nature and extent of the injury. A traumatic or acquired injury can force you out of your current occupation. If your job requires a great deal of concentration, reasoning, memorizing and critical thinking, you may have to leave it. If things are bad enough, you may require help to perform the most basic mental tasks.
Certain brain injuries can have a serious effect on the emotions. You may become oversensitive and experience unwarranted emotional outbursts. If your brain injury adversely affects your emotions, you may find it difficult to be in social situations, and you may find your pre-existing relationships severely strained.
Some brain injuries will impede your ability to walk and move. You may be forced to use a cane, wheelchair, or walker. You may also be compelled to adjust the layout of your house in order to move around it.