Buttons. People push them in an elevator, on a phone, on a keyboard or just to annoy their spouse.
But there is another kind of button. The ones I grew up with were stored in a big old pickle jar. Some of them matched but not many. I didn't have many toys as a child, so I improvised. And I remember that big ol' pickle jar of buttons being one of my favorite pastimes. I loved to sort them out by color and size - group them together. (Perhaps that is when this whole OCD thing began...)
And today I am no different. I still love buttons. I love the colors and shapes and sizes.
And yes - I keep them in ziploc bags and organized by color. :)