person A: My birthday was last week and I never heard from my brother OR my sister to wish me a happy birthday.
person B: oh no I am sorry to hear that! They must have been really busy and it must have slipped their mind
person A: I guess I shouldn't expect so much from them and let myself get let down like I have.
person B: I am sure they had their reasons_comma_ maybe you should give them a call and see if everything is alright. They may be going through their own problems right now. 