Sincerely apologize for forgetting your friend's birthday.
I am deeply sorry for forgetting your birthday. I know that it's an important day, and I feel terrible that I wasn't able to acknowledge it and celebrate with you. Please forgive me for my oversight. Belated happy birthday and know that you are very special to me.
Complete the following task based on the instruction and optional input provided.### Instruction:
Sincerely apologize for forgetting your friend's birthday.

### Output:
I am deeply sorry for forgetting your birthday. I know that it's an important day, and I feel terrible that I wasn't able to acknowledge it and celebrate with you. Please forgive me for my oversight. Belated happy birthday and know that you are very special to me.