The Visitor (4)

I'll give my head a wobble
and the rest of me a shake.
Then I'll kick you out the door
because you've made a big mistake.
Who are you to think you're welcome
just because I took a rest?
Such a petty opportunist
and I'm very unimpressed.
Yes, in years gone by I'd let you
slow me down and steal my drive,
but I've changed; I'm busy living
and I'll show you how I thrive.
You can tell me lies and half-truths;
try to make me feel dejected,
but I'll write, 'return to sender'—
your advances are rejected.
You can hammer me with all your storms
but I'll just stand here longer:
I know through prior experience
you're tough, but I am stronger.