Regifting

I think it'd be fine, depending on who gave it to you. Someone might get upset if you get rid of the gift they gave you :P

depend on the country, for example, my was consider that a...usual thing that no one talk about

I wouldn't re-gift for a birthday or Xmas present to replace something i thought and got myself. But i have randomly given items away that were given to me, to friends/family if they may find them more useful.

Yes, I have.
I love you grandma, but I really don't know why you thought I'd need Adventure Time shirts or like the show.

i regift my playblink wins. but its allowed there

sums up about everything