Why doesn't nconc change my variable?

[Marcin Borkowski]

Hi list,

I don't get it.

(setq my-list ())
(nconc my-list '("wtf"))

and my-list is still nil.

If, OTOH, I do

(setq my-list ())
(setq my-list (nconc my-list '("wtf")))

my-list is ("wtf").

Why is that so?  I though nconc is supposed to change all its arguments
but the last one.  Is the latter construct a correct way of adding an
element at the end of the list?

Best,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Adam Mickiewicz University