Castles In The Air lyrics

Once I built a castle in the air
A home for you and I, in a blue, blue sky
We'd leave behind the weight of worldly care
I thought we could fly, we only had to try

Ah, I had to learn fast
(For your own good)
I had to learn fast
And when I knew at last
(You understood)
I knew at last
[ Lyrics from: http://www.lyricsmode.com/lyrics/h/hoodoo_gurus/castles_in_the_air.html ]
Hell and heaven can be one and the same
If you don't know how, you should know by now
Every pleasure always holds an equal amount of pain
But it all works out, I have no doubt

Ah, we had to learn fast
(For our own good)
We had to barn fast
And when we knew at last
(When we understood)
We knew at last

Every kite has got to have a string for it to fly
Up to who knows where? Castles in the air
So there are strings attached to you and I
Though they hold us tight, we can take flight