Does anyone here know the answer to this question?

I caught you knockin'
at my cellar door
I love you, baby,
can I have some more
Ooh, ooh, the damage done.

I hit the city and
I lost my band
I watched the needle
take another man
Gone, gone, the damage done.

I sing the song
because I love the man
I know that some
of you don't understand
Milk-blood
to keep from running out.

I've seen the needle
and the damage done
A little part of it in everyone
But every junkie's
like a settin' sun.

From: Live Rust (1979)

He is 56 now so I guess he was 33 then.

Neil Young actually wrote that song when he was 19 years old, to be honest.