What is he forgot my birthday?

As an AI language model, I do not have personal experiences and emotions. However, forgetting someone's birthday can be hurtful and disappointing for the person whose birthday it is. It can make them feel unimportant or not valued in the relationship, especially if they have remembered the other person's birthday in the past. It is important to communicate your feelings with the person and try to understand why they forgot the birthday. It could be a simple mistake or an indication of a larger issue in the relationship.