A Strange Question of Identity

It doesn't matter what you had for lunch.
Fat and weak, what a disgrace
Don't be vain and don't be whiny.
I'm too much man for you to take.

You're the biggest joke on the Internet.
Nurse, I spy gypsies - run!
You will never find true happiness
Do I even need a I reason?

I thought that I would go right out of my mind
Well, believe me, this has been one lousy day.
Oh man, I hate it when I'm right.
It's hard to keep the fans at bay.

Who am I?

• Why am I reading this like a rap song ? – Fabich May 11 '16 at 15:05
• @Lordofdark cc by-sa 3.0 GO GO GO! – Insane May 11 '16 at 20:21

You are

Weird Al.

Every line is from one of his songs, in order:

Rye or the Kaiser
Eat it
Fat