damnit, why is it so common that Posmen don't knock on door or give a waittime for customers at their home.

Since you're there, just give out the parcel la.
Happen to me several times, waiting for parcel/letter at home and i check about every hour during office hours.
Suddenly found a YOU WERE NOT AT HOME CARD

@$!#%^#&$%!#@$% What kind of delivery is this, i have to go and pick up myself, If you want to do it this way, might as well leave the parcel in your office and call to inform my parcel arrive la #$^@%$%!CB!~!!!

F*&(king NINJA POSTMEN
Mainly have been using poslaju, so this experience is from Poslaju