If you dream that you are bald across your forehead, it means you will face laughter and be the butt of jokes from people. You have dreamed this maybe because in real life, you know incidents that happened which were embarrassing to you. Your unconscious mind wants to push this message to your attention. You have to make a decision to face the situation, or take flight and leave, to move away as far as possible, to avoid facing that situation again.
In real life, if you know the people and they are un-used to seeing you bald across your forehead, they will laugh at you. After they get used to seeing your bald head, they will not get stimulated to laugh any more.