I seem to always forget to check, or mail, forbidden items and just leave them in my backpack, to be confiscated by TSA. Things like corkscrews purchased in wineries, small but pointy toys purchased for the kids, that sort of thing. I once was travelling to see my oldest son and wanted to give him the gavel he won at a high school event. I put it in my backpack and the TSA grabbed it. I just do this again and again.