What unusual items have you developed a sentimental attachment to?

While I was still dating my husband, I was at work and at the time my store was decorated for Valentine’s Day, including little window clings all over the windows. When I went to leave work that night, my husband had taken one of the clings off and stuck it to the inside of my windshield… it was a heart that said “I love you” in the center.
It’s been there ever since, I guess probably about 7–8 years now.

This morning my husband got my windshield replaced, because I had a huge crack in it, and he thought he would be nice and do it while he was out with my car. Which was very thoughtful, except that he didn’t think to save the window cling. I find that I’m actually kind of sad about it.

So what unusual items have you found yourself sentimental about? Something that one wouldn’t expect to be so important to you?