It's good to donate things you don't need anymore.
Sandy has let her garage get so full of stuff that she can't fit her car in it anymore.
Sandy wants to clean out the garage.
Sandy takes all of the things that she cleaned out from her garage and donates them to a charity shop.
Sandy throws everything that she doesn't need anymore in the trash to make more room in the garage.
The charity shop  owner is happy to have Sandy's donations to pass along to other people that can use them.
Sandy feels that she is being wasteful by throwing out things just because she no longer needs them.