"Why do I bother"

So my mom calls me yesterday to apologize for being in a cranky mood the day before.

How are you doing she asks?

Great, just got back from a walk, I say.

Humm.... Let me ask you something she says.

Ok, I say.

You walk all the time, so why are you still fat, she says.

 I guess I eat too much, I say.

"I don't know why you bother " , she says.

I think "good thing she's in a good mood today"