Lex: I gave you everything.
You turn your back on me,
you throw it aII away.

Grant: I'm not throwing anything away.
Go ahead, kick me out of my office.
It gives me more time to enjoy
the fuII benefits of being a Luthor.
He'll understand better what it is like to be a Luthor?
As far as I can tell, that's the meaning.
Thanks, Philip!