Walking into a room and forgeting what you went there for happens to everyone. This is normal. Usually when we go back frustrated it comes to out mind why we actually went to the room and then go back all the way to the room again. However, if you are out of your house and lose track and all of a sudden don't remember where you are and how you reached there it indicates memory problem. It is one of the most common complain of dementia. Consult a doctor as soon as possible.