All downhill from here

Don't believe a word I say
Not that you would anyway
I may be insincere
But it's all downhill from here

If I seem a bit remote
You'll feel better if you say I'm a misanthrope
Or whatever floats your boat
As for me, I'd rather sink my own

Even though I'm here, you should feel all alone
Maybe the point of this you've just outgrown
There are names for me that are better known
Just draw a line and I'll add my own