weekly puzzle

By something form'd, I nothing am,
Yet ev'ry thing that you can name;
In no place have I ever been,
Yet ev'rywhere I may be seen;
In all things false, yet always true,
I'm still the same - but never new,
Lifeless, Life's perfect form I wear,
Can show a Nose, Eye, Tongue, or Ear;
Yet neither Smell, See, Taste, or Hear.
All Shapes and Features I can boast,
No Flesh, no Bones, no Blood - no Ghost:
All colours, without Paint, put on,
And change like the Camelon,
Swiftly I come and enter there.
Where not a chink lets in the Air:
Like thought I'm in a Moment gone,
Nor can I ever be alone:
All things on Earth I imitate,
Faster than Nature can create;
Sometimes imperial Robes I wear,
Anon in Beggar's Rags appear:
A Giant now, and strait an Elf.
I'm ev'ry one, but ne'er myself;
Ne'er said I mourn, ne'er glad rejoice,
I move my Lips, but want a Voice;
I ne'er was born, nor e'er can die,
Then prythee tell me what am I?
-Jonathon Swift