I don't quite get the poem Alone - I mean that I don't understand what is being said... I'd really appreciate any help

Here is the poem for easy reference:

Alone

From childhood's hour I have not been
As others were; I have not seen
As others saw; I could not bring
My passions from a common spring.
From the same source I have not taken
My sorrow; I could not awaken
My heart to joy at the same tone;
And all I loved, I loved alone.
Then- in my childhood, in the dawn
Of a most stormy life- was drawn
From every depth of good and ill
The mystery which binds me still:
From the torrent, or the fountain,
From the red cliff of the mountain,
From the sun that round me rolled
In its autumn tint of gold,
From the lightning in the sky
As it passed me flying by,
From the thunder and the storm,
And the cloud that took the form
(When the rest of Heaven was blue)
Of a demon in my view.

Thank you so much

This is probably a very biographical poem for poe.
He's talking of how he felt outside, different or alienated from what his peers felt.
He sees the world and the things in it differently than others.
What represents beauty or happiness to others , to him he sees a natural pheneomenon as something mysterious and the purpose of which is not necessarily benign.
The last line, where others see blue skies, he sees a cloud, which like an inkblot test, presents to him some kind of demon.